Update Install-PWA_Firefox_Android.md

screenshots/Install-PWA_Firefox_Android.md

@@ -1,21 +1,25 @@
-# Installing the Kiwix JS PWA on Firefox for Android
+# Installing the PWA and using the OPFS on Firefox for Android
 
 Simply visit **_[pwa.kiwix.org](https://pwa.kiwix.org)_** in Firefox on Android. Read more after the demo:
 
+_(be patient while the demo loads)_
+
 <img src="Install-PWA_Firefox_Android.gif" width="360px" />
 
 See also: [&ensp;[Install PWA and use OPFS in Chrome for Android](Demo-OPFS_Chrome_Android.md)&ensp;]
 
 ## Firefox can install PWAs on Android
 
-**Firefox** supports installing PWAs on Android (but not on Desktop). This is useful because the app runs in its own dedicated session and has
+**Firefox** supports installing PWAs on Android (but not on Desktop). This is worthwhile because the app runs in its own dedicated session and has
 its own icon in your Home Screen.
 
 ## Accessing your ZIM files
 
-As shown in the Demo, Firefox for Android works best when using the Origin Private File System. Loading larger archives from the user-visible File System can be slow and glitchy on Firefox for Android, because the browser attempts to load the whole file into memory. So you are limited
-to files that will fit in the OPFS.
+As shown in the Demo, Firefox for Android works best when using the Origin Private File System. Loading larger archives from the user-visible File System
+can be slow and glitchy on Firefox for Android, because the browser attempts to load the whole file into memory. So you are generally limited to files
+that will fit in the OPFS.
 
-On Chromium browsers, there is a larger quota for the OPFS.
+Firefox currently limits the maximum size of the OPFS to ~10GB. On Chromium browsers, there is usually a much larger quota (limited only by the amount
+of free space in your storage).
 
 See also: [&ensp;[Install PWA and use OPFS in Chrome for Android](Demo-OPFS_Chrome_Android.md)&ensp;]