Yep. While no-download poker usually works best for quick cash games or Sit & Go's you can also play bigger multi-table tournaments; just make sure you have a reliable Internet connection. PokerStars' biggest new sensation, Spin & Go tournaments, can also be played with no-download software.
All of cash games are available on the site's mobile app, so you can play real money poker cash games at PokerStars on the move if you have a WiFi or mobile internet connection.