I like killer sudoku. https://apps.apple.com/app/id1505735640 I play waaay too much. It’s also fun to start with no numbers

I much prefer KenKen. It's very similar to sudoku, but involves arithmetic as part of the clues rather than just logic.

I play the version on the Seattle Times site almost every day: https://www.seattletimes.com/games-kenken/

I'm more into nonograms now but I still enjoy playing Sudokus.

I go in phases where I play and don't play. Kind of like free cell.

Not sure if it’s in android, but iOS has an app called Good Sudoku that’s probably my favorite way to play I’ve ever found (have been casually playing for 20ish years). It easily has the best highlighting that lets you quickly parse position for numbers.

Every night before bed. I’ve been doing that as a mental exercise routine ever since my second bout with Covid left me with a little brain fog. It really does help me with concentration and logical thinking.

I installed a sudoku app on my phone the other day and played it a little bit, it was quite enjoyable.