diff --git a/src/platforms/web/chromium/root/img/app_120.png b/src/platforms/web/chromium/root/img/app_120.png
new file mode 100644
index 00000000..4ec9b3d0
Binary files /dev/null and b/src/platforms/web/chromium/root/img/app_120.png differ
diff --git a/src/platforms/web/chromium/root/img/app_128.png b/src/platforms/web/chromium/root/img/app_128.png
new file mode 100644
index 00000000..70581a0e
Binary files /dev/null and b/src/platforms/web/chromium/root/img/app_128.png differ
diff --git a/src/platforms/web/chromium/root/img/app_144.png b/src/platforms/web/chromium/root/img/app_144.png
new file mode 100644
index 00000000..b525f0d8
Binary files /dev/null and b/src/platforms/web/chromium/root/img/app_144.png differ
diff --git a/src/platforms/web/chromium/root/img/app_152.png b/src/platforms/web/chromium/root/img/app_152.png
new file mode 100644
index 00000000..1fa64d99
Binary files /dev/null and b/src/platforms/web/chromium/root/img/app_152.png differ
diff --git a/src/platforms/web/chromium/root/img/app_192.png b/src/platforms/web/chromium/root/img/app_192.png
new file mode 100644
index 00000000..1ee518cf
Binary files /dev/null and b/src/platforms/web/chromium/root/img/app_192.png differ
diff --git a/src/platforms/web/chromium/root/img/app_256.png b/src/platforms/web/chromium/root/img/app_256.png
new file mode 100644
index 00000000..5ed26b16
Binary files /dev/null and b/src/platforms/web/chromium/root/img/app_256.png differ
diff --git a/src/platforms/web/chromium/root/img/app_384.png b/src/platforms/web/chromium/root/img/app_384.png
new file mode 100644
index 00000000..ba464304
Binary files /dev/null and b/src/platforms/web/chromium/root/img/app_384.png differ
diff --git a/src/platforms/web/chromium/root/img/app_512.png b/src/platforms/web/chromium/root/img/app_512.png
new file mode 100644
index 00000000..de9dafe7
Binary files /dev/null and b/src/platforms/web/chromium/root/img/app_512.png differ
diff --git a/src/platforms/web/chromium/root/img/app_72.png b/src/platforms/web/chromium/root/img/app_72.png
new file mode 100644
index 00000000..ee8a8191
Binary files /dev/null and b/src/platforms/web/chromium/root/img/app_72.png differ
diff --git a/src/platforms/web/chromium/root/img/app_96.png b/src/platforms/web/chromium/root/img/app_96.png
new file mode 100644
index 00000000..a03a11b5
Binary files /dev/null and b/src/platforms/web/chromium/root/img/app_96.png differ
diff --git a/src/platforms/web/chromium/root/index.html b/src/platforms/web/chromium/root/index.html
index b30cf30a..e92b51dd 100644
--- a/src/platforms/web/chromium/root/index.html
+++ b/src/platforms/web/chromium/root/index.html
@@ -4,6 +4,15 @@
         <meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
         <title>Snap4Arduino @AppVersion</title>
         <link rel="icon" href="s4a.ico" type="image/ico">
+        <link rel="manifest" href="manifest.json">
+        <link rel="apple-touch-icon" href="img/app_152.png">
+        <meta name="viewport" content="width=device-width, initial-scale=1">
+        <meta name="theme-color" content="white"/>
+        <meta name="apple-mobile-web-app-capable" content="yes">
+        <meta name="apple-mobile-web-app-status-bar-style" content="black">
+        <meta name="apple-mobile-web-app-title" content="Snap4Arduino">
+        <meta name="msapplication-TileImage" content="img/app_144.png">
+        <meta name="msapplication-TileColor" content="#FFFFFF">
         <script>
             require = function () {};
         </script>
@@ -52,6 +61,9 @@
                 ide;
 
             window.onload = function () {
+                if ('serviceWorker' in navigator) {
+                    navigator.serviceWorker.register('sw.js');
+                }
                 world = new WorldMorph(document.getElementById('world'));
 
                 // keepAlive should be handled at the plugin side
diff --git a/src/platforms/web/chromium/root/manifest.json b/src/platforms/web/chromium/root/manifest.json
new file mode 100644
index 00000000..3888342f
--- /dev/null
+++ b/src/platforms/web/chromium/root/manifest.json
@@ -0,0 +1,51 @@
+{
+  "name": "Snap4Arduino",
+  "short_name": "Snap4Arduino",
+  "icons": [{
+      "src": "img/app_72.png",
+      "sizes": "72x72",
+      "type": "image/png"
+    }, {
+      "src": "img/app_96.png",
+      "sizes": "96x96",
+      "type": "image/png"
+    }, {
+      "src": "img/app_120.png",
+      "sizes": "120x120",
+      "type": "image/png"
+    }, {
+      "src": "img/app_128.png",
+      "sizes": "128x128",
+      "type": "image/png"
+    }, {
+      "src": "img/app_144.png",
+      "sizes": "144x144",
+      "type": "image/png"
+    }, {
+      "src": "img/app_152.png",
+      "sizes": "152x152",
+      "type": "image/png"
+    }, {
+      "src": "img/app_192.png",
+      "sizes": "192x192",
+      "type": "image/png",
+      "purpose": "any maskable"
+    }, {
+      "src": "img/app_256.png",
+      "sizes": "256x256",
+      "type": "image/png"
+    }, {
+      "src": "img/app_384.png",
+      "sizes": "384x384",
+      "type": "image/png"
+    }, {
+      "src": "img/app_512.png",
+      "sizes": "512x512",
+      "type": "image/png"
+    }],
+  "lang": "en-US",
+  "start_url": "./index.html",
+  "display": "standalone",
+  "background_color": "white",
+  "theme_color": "white"
+}
diff --git a/src/platforms/web/chromium/root/sw.js b/src/platforms/web/chromium/root/sw.js
new file mode 100644
index 00000000..6d8c9f16
--- /dev/null
+++ b/src/platforms/web/chromium/root/sw.js
@@ -0,0 +1,776 @@
+var snapVersion = '7.0.4',
+    cacheName = 'snap4arduino-pwa',
+    filesToCache = [
+        'index.html',
+
+        // program
+        'src/morphic.js',
+        'src/symbols.js',
+        'src/widgets.js',
+        'src/blocks.js',
+        'src/threads.js',
+        'src/objects.js',
+        'src/scenes.js',
+        'src/gui.js',
+        'src/paint.js',
+        'src/lists.js',
+        'src/byob.js',
+        'src/tables.js',
+        'src/sketch.js',
+        'src/video.js',
+        'src/maps.js',
+        'src/extensions.js',
+        'src/xml.js',
+        'src/store.js',
+        'src/locale.js',
+        'src/cloud.js',
+        'src/api.js',
+        'src/sha512.js',
+        'src/FileSaver.min.js',
+
+        'src/ypr.js',
+        's4a/arduino.js',
+        's4a/blocks.js',
+        's4a/byob.js',
+        's4a/cloud.js',
+        's4a/extensions.js',
+        's4a/gui.js',
+        's4a/httpserver.js',
+        's4a/lists.js',
+        's4a/morphic.js',
+        's4a/objects.js',
+        's4a/store.js',
+        's4a/threads.js',
+        'plugin/arduino.js',
+        'plugin/gui.js',
+        'plugin/morphic.js',
+        'plugin/objects.js',
+        'plugin/plugin.js',
+        'plugin/threads.js',
+
+        // translations
+        'locale/lang-ar.js',
+        'locale/lang-bg.js',
+        'locale/lang-bn.js',
+        'locale/lang-ca.js',
+        'locale/lang-ca_VA.js',
+        'locale/lang-cs.js',
+        'locale/lang-de.js',
+        'locale/lang-dk.js',
+        'locale/lang-el.js',
+        'locale/lang-eo.js',
+        'locale/lang-es.js',
+        'locale/lang-et.js',
+        'locale/lang-eu.js',
+        'locale/lang-fi.js',
+        'locale/lang-fr.js',
+        'locale/lang-gl.js',
+        'locale/lang-he.js',
+        'locale/lang-hi.js',
+        'locale/lang-hr.js',
+        'locale/lang-hu.js',
+        'locale/lang-ia.js',
+        'locale/lang-id.js',
+        'locale/lang-it.js',
+        'locale/lang-ja_HIRA.js',
+        'locale/lang-ja.js',
+        'locale/lang-kn.js',
+        'locale/lang-ko.js',
+        'locale/lang-ml.js',
+        'locale/lang-nl.js',
+        'locale/lang-no.js',
+        'locale/lang-pl.js',
+        'locale/lang-pt_BR.js',
+        'locale/lang-pt.js',
+        'locale/lang-ro.js',
+        'locale/lang-ru.js',
+        'locale/lang-si.js',
+        'locale/lang-sk.js',
+        'locale/lang-sv.js',
+        'locale/lang-ta.js',
+        'locale/lang-te.js',
+        'locale/lang-tr.js',
+        'locale/lang-ua.js',
+        'locale/lang-zh_CN.js',
+        'locale/lang-zh_TW.js',
+
+        's4a/lang-ca.js',
+        's4a/lang-cs.js',
+        's4a/lang-de.js',
+        's4a/lang-es.js',
+        's4a/lang-et.js',
+        's4a/lang-eu.js',
+        's4a/lang-fr.js',
+        's4a/lang-gl.js',
+        's4a/lang-he.js',
+        's4a/lang-id.js',
+        's4a/lang-it.js',
+        's4a/lang-ko.js',
+        's4a/lang-nl.js',
+        's4a/lang-pt.js',
+        's4a/lang-pt_BR.js',
+        's4a/lang-ru.js',
+        's4a/lang-sv.js',
+        's4a/lang-tr.js',
+        's4a/lang-ua.js',
+        's4a/lang-uk.js',
+        's4a/lang-zh_CN.js',
+        's4a/lang-zh_TW.js',
+
+        //libraries
+        'libraries/LIBRARIES',
+
+        'libraries/animation_module.xml',
+        'libraries/apl.xml',
+        'libraries/audioComp_module.xml',
+        'libraries/bar-charts.xml',
+        'libraries/biginteger.js',
+        'libraries/bignumbers.xml',
+        'libraries/bignums.js',
+        'libraries/bbtSnapExtension.js',
+        'libraries/cases.xml',
+        'libraries/colors.xml',
+        'libraries/Eisenbergification.xml',
+        'libraries/frequency_distribution_module.xml',
+        'libraries/httpBlocks.xml',
+        'libraries/HummingbirdBlocks.xml',
+        'libraries/iteration-composition.xml',
+        'libraries/leap-library.xml',
+        'libraries/list-utilities.xml',
+        'libraries/localstorage_module.xml',
+        'libraries/make-variables.xml',
+        'libraries/maps_module.xml',
+        'libraries/parallel_module.xml',
+        'libraries/pixel_module.xml',
+        'libraries/schemeNumber.js',
+        'libraries/serial_module.xml',
+        'libraries/signada.js',
+        'libraries/signada.xml',
+        'libraries/speech_module.xml',
+        'libraries/stream-tools.xml',
+        'libraries/strings.xml',
+        'libraries/textCostumes_module.xml',
+        'libraries/try-catch.xml',
+        'libraries/variadic-reporters.xml',
+        'libraries/word-sentence.xml',
+
+        'libraries/scale.xml',
+        'libraries/snapJrLib.xml',
+        'libraries/snapJrPlusLib.xml',
+        'libraries/i2c.xml',
+        'libraries/SA5Firmata_tone.xml',
+        'libraries/SA5Firmata_ir.xml',
+        'libraries/TdRSTEAMv1.xml',
+        'libraries/TdRSTEAMv2.xml',
+        'libraries/imagina.xml',
+        'libraries/echidna.xml',
+        'libraries/nodeMCU.xml',
+        'libraries/phiro.xml',
+        'libraries/NeoPixel.xml',
+        'libraries/braccio.xml',
+        'libraries/Creative_Robotix.xml',
+
+        //costumes
+        'Costumes/COSTUMES',
+
+        'Costumes/abby-a.svg',
+        'Costumes/abby-b.svg',
+        'Costumes/abby-c.svg',
+        'Costumes/abby-d.svg',
+        'Costumes/airplane2.png',
+        'Costumes/alonzo.png',
+        'Costumes/Alonzo3D.png',
+        'Costumes/alonzo.svg',
+        'Costumes/amon.gif',
+        'Costumes/anina_pop_down.png',
+        'Costumes/anina_pop_front.png',
+        'Costumes/anina_pop_L_arm.png',
+        'Costumes/anina_pop_left.png',
+        'Costumes/anina_pop_R_arm.png',
+        'Costumes/anina_pop_right.png',
+        'Costumes/anina_pop_stand.png',
+        'Costumes/anina_R_cross.png',
+        'Costumes/anina_stance.png',
+        'Costumes/anina_top_freeze.png',
+        'Costumes/anina_top_L_step.png',
+        'Costumes/anina_top_R_step.png',
+        'Costumes/anina_top_stand.png',
+        'Costumes/anna01.png',
+        'Costumes/anna02.png',
+        'Costumes/anna03.png',
+        'Costumes/anna04.png',
+        'Costumes/anna05.png',
+        'Costumes/anna06.png',
+        'Costumes/anna07b.png',
+        'Costumes/anna07c.png',
+        'Costumes/anna07.png',
+        'Costumes/anna08.png',
+        'Costumes/anna09.png',
+        'Costumes/anna10.png',
+        'Costumes/anna11.png',
+        'Costumes/anna12.png',
+        'Costumes/anna-a.png',
+        'Costumes/anna-b.png',
+        'Costumes/apple.svg',
+        'Costumes/arrow1-a.svg',
+        'Costumes/arrow1-b.svg',
+        'Costumes/arrow1-c.svg',
+        'Costumes/arrow1-d.svg',
+        'Costumes/avery-a.svg',
+        'Costumes/avery-b.svg',
+        'Costumes/avery_walking-a.svg',
+        'Costumes/avery_walking-b.svg',
+        'Costumes/avery_walking-c.svg',
+        'Costumes/avery_walking-d.svg',
+        'Costumes/AZ_pop_down.png',
+        'Costumes/AZ_pop_front.png',
+        'Costumes/AZ_pop_L_arm.png',
+        'Costumes/AZ_pop_left.png',
+        'Costumes/AZ_pop_R_arm.png',
+        'Costumes/AZ_pop_right.png',
+        'Costumes/AZ_pop_stand.png',
+        'Costumes/AZ_stance.png',
+        'Costumes/AZ_top_freeze.png',
+        'Costumes/AZ_top_L_step.png',
+        'Costumes/AZ_top_R_cross.png',
+        'Costumes/AZ_top_R_step.png',
+        'Costumes/AZ_top_stand.png',
+        'Costumes/ball-a.svg',
+        'Costumes/ball-b.svg',
+        'Costumes/ball-c.svg',
+        'Costumes/ball-d.svg',
+        'Costumes/ballerina-a.svg',
+        'Costumes/ballerina-b.svg',
+        'Costumes/ballerina-c.svg',
+        'Costumes/ballerina-d.svg',
+        'Costumes/ball-e.svg',
+        'Costumes/balloon1-a.svg',
+        'Costumes/balloon1-b.svg',
+        'Costumes/balloon1-c.svg',
+        'Costumes/ball-soccer.svg',
+        'Costumes/bananas.svg',
+        'Costumes/baseball.svg',
+        'Costumes/basketball.svg',
+        'Costumes/bass.svg',
+        'Costumes/bat1-a_.svg',
+        'Costumes/bat1-b_.svg',
+        'Costumes/bat2-a_.svg',
+        'Costumes/bat2-b_.svg',
+        'Costumes/beachball.svg',
+        'Costumes/bear2-a.svg',
+        'Costumes/bear2-b.svg',
+        'Costumes/beetle.svg',
+        'Costumes/bell1.svg',
+        'Costumes/bells-a.svg',
+        'Costumes/bells-b.svg',
+        'Costumes/bowl-a.svg',
+        'Costumes/bowtie-a.svg',
+        'Costumes/bowtie-b.svg',
+        'Costumes/boy1-standing.gif',
+        'Costumes/boy1-walking.gif',
+        'Costumes/boy2.gif',
+        'Costumes/boy3.gif',
+        'Costumes/building-a.svg',
+        'Costumes/building-b.svg',
+        'Costumes/building-c.svg',
+        'Costumes/building-d.svg',
+        'Costumes/building-e.svg',
+        'Costumes/building-f.svg',
+        'Costumes/building-g.svg',
+        'Costumes/building-h.svg',
+        'Costumes/building-i.svg',
+        'Costumes/building-j.svg',
+        'Costumes/bus.png',
+        'Costumes/butterfly1-a.svg',
+        'Costumes/butterfly1-b_.svg',
+        'Costumes/butterfly2_.svg',
+        'Costumes/butterfly3_.svg',
+        'Costumes/button1.svg',
+        'Costumes/button2-a.svg',
+        'Costumes/button2-b.svg',
+        'Costumes/button3-a.svg',
+        'Costumes/button3-b.svg',
+        'Costumes/button4-a.svg',
+        'Costumes/button4-b.svg',
+        'Costumes/button5-a.svg',
+        'Costumes/button5-b.svg',
+        'Costumes/cake-a.svg',
+        'Costumes/cake-b.svg',
+        'Costumes/calvrett_jumping.png',
+        'Costumes/calvrett_thinking.png',
+        'Costumes/candle1-a.svg',
+        'Costumes/candle1-b.svg',
+        'Costumes/candles1.svg',
+        'Costumes/candles2.svg',
+        'Costumes/car-bug.png',
+        'Costumes/cassy-a.png',
+        'Costumes/cassy-b.png',
+        'Costumes/cassy-c.png',
+        'Costumes/cassy_dance-a.png',
+        'Costumes/cassy_dance-b.png',
+        'Costumes/cassy_dance-c.png',
+        'Costumes/cassy_dance-d.png',
+        'Costumes/cassy-d.png',
+        'Costumes/cat2.gif',
+        'Costumes/cat2.svg',
+        'Costumes/cat3.png',
+        'Costumes/cat4.png',
+        'Costumes/cat5.gif',
+        'Costumes/catherine-a.png',
+        'Costumes/catherine-b.png',
+        'Costumes/catherine-c.png',
+        'Costumes/catherine-d.png',
+        'Costumes/champ99-a.png',
+        'Costumes/champ99-b.png',
+        'Costumes/champ99-c.png',
+        'Costumes/champ99-d.png',
+        'Costumes/champ99-e.png',
+        'Costumes/champ99-f.png',
+        'Costumes/champ99-g.png',
+        'Costumes/cheesy-puffs.png',
+        'Costumes/cloud-a.svg',
+        'Costumes/cloud-b.svg',
+        'Costumes/cloud-c.svg',
+        'Costumes/cloud-d.svg',
+        'Costumes/cloud.svg',
+        'Costumes/cm_pop_L_arm.png',
+        'Costumes/cm_pop_R_arm.png',
+        'Costumes/cm_top_L_cross.png',
+        'Costumes/cm_top_L_leg.png',
+        'Costumes/cm_top_R_cross.png',
+        'Costumes/cm_top_ready.png',
+        'Costumes/cm_top_R_leg.png',
+        'Costumes/cm_top_stand.png',
+        'Costumes/convertible1.png',
+        'Costumes/convertible2.png',
+        'Costumes/convertible3.svg',
+        'Costumes/cowbell.svg',
+        'Costumes/crab-a.svg',
+        'Costumes/crab-b.svg',
+        'Costumes/creature1-a.svg',
+        'Costumes/creature1-b.svg',
+        'Costumes/creature1-c.svg',
+        'Costumes/cymbal-a.svg',
+        'Costumes/cymbal-b.svg',
+        'Costumes/dan-a.png',
+        'Costumes/dan-b.png',
+        'Costumes/dani-a.svg',
+        'Costumes/dani-b.svg',
+        'Costumes/dani-c.svg',
+        'Costumes/dee-a.svg',
+        'Costumes/dee-b.svg',
+        'Costumes/dee-c.svg',
+        'Costumes/dee-d.svg',
+        'Costumes/dee-e.svg',
+        'Costumes/devin-a.svg',
+        'Costumes/devin-b.svg',
+        'Costumes/devin-c.svg',
+        'Costumes/devin-d.svg',
+        'Costumes/dinosaur1-a.svg',
+        'Costumes/dinosaur1-b.svg',
+        'Costumes/dinosaur1-c.svg',
+        'Costumes/dinosaur1-d.svg',
+        'Costumes/dinosaur1-e.svg',
+        'Costumes/dinosaur1-f.svg',
+        'Costumes/dinosaur1-g.svg',
+        'Costumes/dinosaur2-a.svg',
+        'Costumes/dinosaur2-b.svg',
+        'Costumes/dinosaur3.svg',
+        'Costumes/diver1.svg',
+        'Costumes/diver2.svg',
+        'Costumes/dm_freeze.png',
+        'Costumes/dm_pop_down.png',
+        'Costumes/dm_pop_front.png',
+        'Costumes/dm_pop_L_arm.png',
+        'Costumes/dm_pop_left.png',
+        'Costumes/dm_pop_R_arm.png',
+        'Costumes/dm_pop_right.png',
+        'Costumes/dm_pop_stand.png',
+        'Costumes/dm_stance.svg',
+        'Costumes/dm_top_L_leg.png',
+        'Costumes/dm_top_R_leg.png',
+        'Costumes/dm_top_stand.png',
+        'Costumes/dog1-a.svg',
+        'Costumes/dog1-b.svg',
+        'Costumes/dog2-a.svg',
+        'Costumes/dog2-b.svg',
+        'Costumes/dog2-c.svg',
+        'Costumes/dog_puppy_back.png',
+        'Costumes/dog_puppy_right.png',
+        'Costumes/dog_puppy_side.png',
+        'Costumes/dog_puppy_sit.png',
+        'Costumes/donut.svg',
+        'Costumes/dove1-a.svg',
+        'Costumes/dove1-b.svg',
+        'Costumes/dove2-a.svg',
+        'Costumes/dove2-b.svg',
+        'Costumes/dragon1-a.svg',
+        'Costumes/dragon1-b.png',
+        'Costumes/dragon1-b.svg',
+        'Costumes/dragon2.gif',
+        'Costumes/drum1-a.svg',
+        'Costumes/drum1-b.svg',
+        'Costumes/drum2-a.svg',
+        'Costumes/drum2-b.svg',
+        'Costumes/drum_bass-a.svg',
+        'Costumes/drum_bass-b.svg',
+        'Costumes/drums_conga-a.svg',
+        'Costumes/drums_conga-b.svg',
+        'Costumes/drum_snare-a.svg',
+        'Costumes/drum_snare-b.svg',
+        'Costumes/duck.svg',
+        'Costumes/earth.svg',
+        'Costumes/elephant-a_.svg',
+        'Costumes/elephant-b_.svg',
+        'Costumes/fire_hydrant.png',
+        'Costumes/fish1.svg',
+        'Costumes/fish2.svg',
+        'Costumes/fish3.svg',
+        'Costumes/flower_shape.svg',
+        'Costumes/football_running.png',
+        'Costumes/football_standing.png',
+        'Costumes/fortunecookie.png',
+        'Costumes/fox.svg',
+        'Costumes/frog.svg',
+        'Costumes/fruit_platter.png',
+        'Costumes/fruitsalad.svg',
+        'Costumes/ghost1_.svg',
+        'Costumes/ghost2-a.svg',
+        'Costumes/ghost2-b.svg',
+        'Costumes/ghoul-a.svg',
+        'Costumes/ghoul-b.svg',
+        'Costumes/gift-a.svg',
+        'Costumes/gift-b.svg',
+        'Costumes/girl1-standing.gif',
+        'Costumes/girl1-walking.gif',
+        'Costumes/girl2-shouting.gif',
+        'Costumes/girl2-standing.gif',
+        'Costumes/girl3-basketball.gif',
+        'Costumes/girl3-running.gif',
+        'Costumes/girl3-standing.gif',
+        'Costumes/glasses.svg',
+        'Costumes/glass_water-a.svg',
+        'Costumes/glass_water-b.svg',
+        'Costumes/green_flag.svg',
+        'Costumes/guitar_bass.svg',
+        'Costumes/guitar_electric.svg',
+        'Costumes/guitar.svg',
+        'Costumes/hannah-a.png',
+        'Costumes/hannah-b.png',
+        'Costumes/hannah-c.png',
+        'Costumes/hat_beanie.svg',
+        'Costumes/hat_party2-a.svg',
+        'Costumes/Hat.svg',
+        'Costumes/hat_winter.svg',
+        'Costumes/hat_wizard.svg',
+        'Costumes/headband.svg',
+        'Costumes/heart_code.svg',
+        'Costumes/heart_face.svg',
+        'Costumes/heart_love_it.svg',
+        'Costumes/heart_purple.svg',
+        'Costumes/heart_red.svg',
+        'Costumes/heart_smile.svg',
+        'Costumes/heart_sweet.svg',
+        'Costumes/helicopter.png',
+        'Costumes/hippo1-a.svg',
+        'Costumes/hippo1-b.svg',
+        'Costumes/holly1.svg',
+        'Costumes/holly2.svg',
+        'Costumes/home_button.svg',
+        'Costumes/horse1-a.svg',
+        'Costumes/horse1-b.svg',
+        'Costumes/jaime-a.png',
+        'Costumes/jaime-b.png',
+        'Costumes/jaime_walking-a.png',
+        'Costumes/jaime_walking-b.png',
+        'Costumes/jaime_walking-c.png',
+        'Costumes/jaime_walking-d.png',
+        'Costumes/jaime_walking-e.png',
+        'Costumes/jay.gif',
+        'Costumes/jeans-a.svg',
+        'Costumes/jeans-b.svg',
+        'Costumes/jodi.gif',
+        'Costumes/jo_pop_down.png',
+        'Costumes/jo_pop_front.png',
+        'Costumes/jo_pop_L_arm.png',
+        'Costumes/jo_pop_left.png',
+        'Costumes/jo_pop_R_arm.png',
+        'Costumes/jo_pop_right.png',
+        'Costumes/jo_pop_stand.png',
+        'Costumes/jo_stance.png',
+        'Costumes/jo_top_L_cross.png',
+        'Costumes/jo_top_L_leg.png',
+        'Costumes/jo_top_R_cross.png',
+        'Costumes/jo_top_R_leg.png',
+        'Costumes/jo_top_stand.png',
+        'Costumes/keyboard-a.svg',
+        'Costumes/keyboard-b.svg',
+        'Costumes/keyboard-c.svg',
+        'Costumes/keyboard-d.svg',
+        'Costumes/key.svg',
+        'Costumes/khalid-a.png',
+        'Costumes/Khalid-b.png',
+        'Costumes/khalid-c.png',
+        'Costumes/khalid-d.png',
+        'Costumes/knight.svg',
+        'Costumes/ladybug2-a.svg',
+        'Costumes/ladybug2-b.svg',
+        'Costumes/ladybug2.svg',
+        'Costumes/lamp.png',
+        'Costumes/laptop.svg',
+        'Costumes/lb_pop_down.png',
+        'Costumes/lb_pop_front.png',
+        'Costumes/lb_pop_L_arm.png',
+        'Costumes/lb_pop_left.png',
+        'Costumes/lb_pop_R_arm.png',
+        'Costumes/lb_pop_right.png',
+        'Costumes/lb_pop_stand.png',
+        'Costumes/lb_stance.png',
+        'Costumes/lb_top_L_cross.png',
+        'Costumes/lb_top_L_leg.png',
+        'Costumes/lb_top_R_cross.png',
+        'Costumes/lb_top_R_leg.png',
+        'Costumes/lb_top_stand.png',
+        'Costumes/lightning.svg',
+        'Costumes/lion-a.svg',
+        'Costumes/lion-b.svg',
+        'Costumes/lioness.svg',
+        'Costumes/lorenz01.png',
+        'Costumes/lorenz02.png',
+        'Costumes/lorenz03.png',
+        'Costumes/lorenz04.png',
+        'Costumes/lorenz05.png',
+        'Costumes/lorenz06.png',
+        'Costumes/lorenz07b.png',
+        'Costumes/lorenz07.png',
+        'Costumes/magiccarpet.png',
+        'Costumes/magicwand.svg',
+        'Costumes/marble-building.png',
+        'Costumes/marissa-crouching.gif',
+        'Costumes/marissa.gif',
+        'Costumes/marissa-sitting.gif',
+        'Costumes/maya.png',
+        'Costumes/microphonestand.svg',
+        'Costumes/microphone.svg',
+        'Costumes/monkey1-a.svg',
+        'Costumes/monkey1-b.svg',
+        'Costumes/monkey2-a.svg',
+        'Costumes/monkey2-b.svg',
+        'Costumes/monkey2-c.svg',
+        'Costumes/mori.png',
+        'Costumes/mouse1-a.svg',
+        'Costumes/mouse1-b.svg',
+        'Costumes/muffin-a.svg',
+        'Costumes/muffin-b.svg',
+        'Costumes/octopus-a.svg',
+        'Costumes/octopus-b.svg',
+        'Costumes/orange2-a.svg',
+        'Costumes/orange2-b.svg',
+        'Costumes/orange2-c.svg',
+        'Costumes/orange.svg',
+        'Costumes/paddle.svg',
+        'Costumes/palmtree.gif',
+        'Costumes/parrot2-a.svg',
+        'Costumes/parrot2-b.svg',
+        'Costumes/parrot-a.svg',
+        'Costumes/parrot-b.svg',
+        'Costumes/partyhat1.svg',
+        'Costumes/paul.gif',
+        'Costumes/pencil-a.svg',
+        'Costumes/pencil-b.svg',
+        'Costumes/penguin1.svg',
+        'Costumes/penguin1_talk-a.svg',
+        'Costumes/penguin1_talk-b.svg',
+        'Costumes/penguin2.svg',
+        'Costumes/penguin2_talk-a.svg',
+        'Costumes/penguin2_talk-b.svg',
+        'Costumes/penguin3-a.svg',
+        'Costumes/penguin3-b.svg',
+        'Costumes/penguin3-c.svg',
+        'Costumes/piano.svg',
+        'Costumes/planet2.svg',
+        'Costumes/princess.svg',
+        'Costumes/prince.svg',
+        'Costumes/rainbow.svg',
+        'Costumes/referee.gif',
+        'Costumes/reindeer.svg',
+        'Costumes/robot1.svg',
+        'Costumes/rocks.svg',
+        'Costumes/rory.png',
+        'Costumes/ruby-a.png',
+        'Costumes/ruby-b.png',
+        'Costumes/sail-boat.png',
+        'Costumes/sam.gif',
+        'Costumes/saxophone-a.svg',
+        'Costumes/saxophone-b.svg',
+        'Costumes/scarf1.svg',
+        'Costumes/scarf2.svg',
+        'Costumes/shark-a_.svg',
+        'Costumes/shark-b_.svg',
+        'Costumes/shark-c_.svg',
+        'Costumes/shirt2-a2.svg',
+        'Costumes/shirt2-a.svg',
+        'Costumes/shirt-a.svg',
+        'Costumes/shirt_blouse.svg',
+        'Costumes/shirt-b.svg',
+        'Costumes/shirt_collar-a.svg',
+        'Costumes/shirt_collar-b.svg',
+        'Costumes/shirt_collar-c.svg',
+        'Costumes/shoes1.svg',
+        'Costumes/shoes2.svg',
+        'Costumes/Singer1.svg',
+        'Costumes/skates.svg',
+        'Costumes/sl_pop_L_arm.png',
+        'Costumes/sl_pop_R_arm.png',
+        'Costumes/sl_top_L_cross.png',
+        'Costumes/sl_top_L_leg.png',
+        'Costumes/sl_top_R_cross.png',
+        'Costumes/sl_top_ready.png',
+        'Costumes/sl_top_R_leg.png',
+        'Costumes/sl_top_stand.png',
+        'Costumes/snowflake.svg',
+        'Costumes/snowman.svg',
+        'Costumes/spaceship-a.svg',
+        'Costumes/spaceship-b.svg',
+        'Costumes/speaker.svg',
+        'Costumes/squirrel1.png',
+        'Costumes/star1.svg',
+        'Costumes/star2.svg',
+        'Costumes/star3-a.svg',
+        'Costumes/star3-b.svg',
+        'Costumes/starfish-a.svg',
+        'Costumes/starfish-b_.svg',
+        'Costumes/stop.svg',
+        'Costumes/street-cleaner-mit.png',
+        'Costumes/sunglasses1.svg',
+        'Costumes/sunglasses2.svg',
+        'Costumes/sun.svg',
+        'Costumes/tabla-a.svg',
+        'Costumes/tabla-b.svg',
+        'Costumes/taco-a.svg',
+        'Costumes/taco-b.svg',
+        'Costumes/tennisball.png',
+        'Costumes/trampoline.png',
+        'Costumes/tree1.svg',
+        'Costumes/tree2.svg',
+        'Costumes/tree-lights-a.svg',
+        'Costumes/tree-lights-b.svg',
+        'Costumes/trees-a.svg',
+        'Costumes/trees-b.svg',
+        'Costumes/trombone-a.svg',
+        'Costumes/trombone-b.svg',
+        'Costumes/trumpet-a2.svg',
+        'Costumes/trumpet-a.svg',
+        'Costumes/ukulele.svg',
+        'Costumes/umbrella.png',
+        'Costumes/unicorn1.png',
+        'Costumes/unicorn.svg',
+        'Costumes/vest-a.svg',
+        'Costumes/vest-b.svg',
+        'Costumes/wanda.svg',
+        'Costumes/watermelon-a.svg',
+        'Costumes/watermelon-b.svg',
+        'Costumes/watermelon-c.svg',
+        'Costumes/witch.svg',
+        'Costumes/wizard1.svg',
+        'Costumes/wizard2.svg',
+        'Costumes/wizard.svg',
+
+        'Costumes/tortugaJr.png',
+        'Costumes/fantastic.png',
+        'Costumes/beetleJr.svg',
+        'Costumes/cat2Jr.svg',
+        'Costumes/echidna.png',
+        'Costumes/echidna.svg',
+        'Costumes/echidnaJr.png',
+
+        // Backgrounds
+        'Backgrounds/BACKGROUNDS',
+
+        'Backgrounds/atom_playground.jpg',
+        'Backgrounds/bedroom1.gif',
+        'Backgrounds/bedroom2.gif',
+        'Backgrounds/berkeley_mural.jpg',
+        'Backgrounds/brick-wall-and-stairs.jpg',
+        'Backgrounds/brick-wall1.jpg',
+        'Backgrounds/brick-wall2.jpg',
+        'Backgrounds/desert.gif',
+        'Backgrounds/night_city_with_street.gif',
+        'Backgrounds/party_room.jpg',
+        'Backgrounds/pathway.jpg',
+        'Backgrounds/xy-grid.gif',
+        
+        // Sounds
+        'Sounds/SOUNDS',
+
+        'Sounds/Cat.mp3',
+        'Sounds/Chord.wav',
+        'Sounds/Dog1.wav',
+        'Sounds/Dog2.wav',
+        'Sounds/FingerSnap.wav',
+        'Sounds/Kitten.wav',
+        'Sounds/Laugh-female.wav',
+        'Sounds/Laugh-male1.wav',
+        'Sounds/Laugh-male2.wav',
+        'Sounds/Laugh-male3.mp3',
+        'Sounds/Meow.wav',
+        'Sounds/Pop.wav',
+        
+        // Examples
+        'Examples/EXAMPLES',
+
+        'Examples/animal-game.xml',
+        'Examples/Codification.xml',
+        'Examples/copter.xml',
+        'Examples/count-change.xml',
+        'Examples/icecream-visual.xml',
+        'Examples/JSfunctions.xml',
+        'Examples/live-tree.xml',
+        'Examples/swimmer.xml',
+        'Examples/tree.xml',
+        'Examples/vee.xml',
+
+        'Examples/Bumpy Cat.xml',
+        'Examples/Force Meter.xml',
+        'Examples/Line Tracer.xml',
+        'Examples/Simon.xml',
+        'Examples/Etch-a-Sketch.xml',
+        'Examples/Gauge.xml',
+        'Examples/MeArm.xml',
+        'Examples/Robotic eye.xml',
+        'Examples/Theremin.xml',
+    ];
+
+/* Start the service worker and cache all of the app's content */
+self.addEventListener('install', function(e) {
+    e.waitUntil(
+        caches.open(cacheName).then(function(cache) {
+            return cache.addAll(filesToCache);
+        })
+    );
+});
+
+self.addEventListener('activate', (evt) => {
+    evt.waitUntil(
+        caches.keys().then((keyList) => {
+            return Promise.all(keyList.map((key) => {
+                if (key !== cacheName) {
+                    return caches.delete(key);
+                }
+            }));
+        })
+    );
+    self.clients.claim();
+});
+
+/* Serve cached content when offline */
+self.addEventListener('fetch', function(e) {
+    e.respondWith(
+        caches.match(
+            e.request,
+            {'ignoreSearch': true}
+        ).then(function(response) {
+            return response || fetch(e.request);
+        })
+    );
+});