The best alternatives to cotrio are Nuzzle, Dragonbox Algebra, and Numberful. If these 3 options don't work for you, we've listed a few more alternatives below.
What do you think of cotrio?
SeedLegals— Close your next round faster - All your legals in one place
Do you like Sudoku? Then play Nuzzle! If you enjoy number puzzle games, it's similar to Sudoku, but a harder game is waiting for you. You should align numbers from top to bottom and from left to right. There is no time restriction. But that does not mean it will last forever :)