I know it seems hopeless but there really are some great mobile games out there which do not try to trick you or screw you around to get your money.
If you like puzzle games (I assume you do, since you mention Andoku Sudoku), you should check out games by Pyrosphere[0]. Especially look at Lazors[1] and The Weaver[2]. Also fun to play is Hoplite[3] and the training mode in Lichess[4]. All of these games are free, though Hoplite lets you pay to unlock an extended endgame, it isn't necessary at all.
[1] https://play.google.com/store/apps/details?id=com.graveck.st...