Good Old Tetris - Play Tetris Online. The game that will never get old.
Ubisoft Club - Ubisoft Club app enables you to get updates about your favorite games timely.
Word Tetris - Tetris with words
itch.io - An online game marketplace and community.
Tetris Blitz - Race against the clock in a two-minute blitz to clear lines and rack up points before time runs out.
GOG.com - DRM-free game store, selling both new and old titles. No clients required.