NullpoMino - NullpoMino is an open-source action puzzle game that works on the Java platform.
Y-Productive - Keep your work and distractions under control
Tetris Blitz - Race against the clock in a two-minute blitz to clear lines and rack up points before time runs out.
Serene - The macOS app to get your focus back
Blockinger - An open source Tetris clone for Android.
Freedom.to - Freedom is a productivity hack that lets you block apps, websites or the entire Internet on iPhones, iPads, Windows and Mac computers.