Sonic Dash

There is some arguing as to whether this is "free" as it's rammed with in-app purchases, but there's no dispute as to its quality. Sonic's latest mobile game is, appropriately, an endless runner, with the hedgehog jumping left and right to avoid obstacles placed around its familiar green worlds.

credit: techradar.com

https://play.google.com/store/apps/details?id=com.sega.sonicdash