How to make a super small Android application for your website
Surprisingly, a minimum single Activity “Hello World” application compiled in Android Studio would take 2-4 MB. This size is not too much compared to most apps. It is actually in the acceptable range for Lite apps that we checked last time. But this is quite a lot when we think of the amount of functionality we've got. Let’s take a look inside.
However, at the Play Market Google packs and signs our app for us! Thus, the final APK size becomes 20.6 KB. Yes, Play Store signatures can take half of app size 😄 This size can probably vary depending on the minimum SDK version since Google have to use compatible signature schemes. For example, for the minimum SDK 21 (Android 5.0) Google employs JAR signing first before applying the v2 APK signature scheme.
Google Play also adds some split placeholders for bundling functionality even if we don't split the app. But unfortunately app bundling does not support app versioning for a particular Android version, so there is no way to remove this extra 10KB added by Google Play. But still this app is super small compared to others. Google reports our app's size actually 5MB smaller than the peers' median!