> 25MB ad-filled app
I really started noticing this since starting to use F-Droid, for a lot of simple apps in the Google Play Store, you can get the same functionality, with zero ads and a much smaller bundle size in F-Droid.
For example this app from F-Droid, which shows your GPS location & coordinates, weighs in at _48KiB_! https://f-droid.org/en/packages/com.borneq.heregpslocation/ (disclaimer: I have not tried the app, it was just the first result that came up from a search).
It's pretty cool to see that yes, it's perfectly possible to build lightweight Android apps; and it's really a question of what you put in the bundle.