self-promotion caveat: I'm building my sudoku game to be offline and fully accessible: https://play.google.com/store/apps/details?id=digital.cyberpuffin.sudoku
The only thing that might constitute an "ad" is a button on the main menu that leads to a promotion page for my print-on-demand book.
Some more context: Godot established the "Godot Development Fund" to accept donations directly (https://lemmy.ml/post/4815592).