Nitro Nation is a very pretty drag racing game for mobile devices, with races won and lost through gear changes and correct use of nitrus.  It has lots of officially licensed cars, an impressive array of upgrades (that still keep the game balanced), and the ability to fully customise the look of your cars that rivals most pc & console games.  It’s a fun game with a lot of polish, that feels like playing a Fast & Furious game (if the F&F games weren’t all garbage).

UPDATE: This Beta Is No Longer Available