If you've been jonesing for a new racing game you can carry in your pocket, consider Sonic & All-Stars Racing Transformed, which is now free on the App Store as well as Google Play. See, Android users? They didn't forget you. I told you the day would come, and it did. Gotta go fast!
The game was previously available for $4.99, so if you purchased it at sticker price, too bad for you. Actually, it's cool -- Sega has gifted players who took part in the original launch a VIP Pass (valued at $4.99) which will unlock four playable characters, including Sonic. So it's like you just invested in your gaming future, really.
On April 29, Metal Sonic and Wreck-It Ralph will be added to the game as playable racers as well. If you were looking for a reason to pull the trigger, there's no better time to pick up the app than now, since it's, well, free. If you need driving music, might I suggest "I'm Your Torpedo" or "MUZiC?"