A silly little situated app for helping kids with school. This one drills addition by creating little 2x2 sudoku-like puzzles.

https://git.sr.ht/~akkartik/sum-grid.love (directory)
https://tilde.club/~akkartik/sum-grid.love (.love file; sorry)

Easy to run, a single download runs anywhere (including Android and iOS) once you install LÖVE (https://love2d.org; 5MB download), can be modified as it runs, and now can also be slowed down so you can see what it's doing (https://merveilles.town/@akkartik/111422018573320117)