[unix_distributions][android] List app stores

[LukeShortCloud]

• Amazon Appstore = Amazon's own app store provides an alternative to the Google Play Store.
• APKUpdater = Checks for local app updates from various app stores: APKMirror, Aptoide, F-Droid, and Google Play.
• Aptoide = A community-driven app store that provides an alternative to the Google Play Store. All apps on this platform are free (but not necessarily open source).
• F-Droid = Free and open source software.
• Google Play Store = The official app store from Google for Android.