Available from the App Marketplace.
Full Review after the jump:
Cost: Free – for more features, an upgrade is needed
Live Tile: No. It’s a damn piano.
Background Update: FOR WHAT? IT’S A PIANO. They don’t change very often.
Push Notifications: See above.
Pros: It’s a fun little app, with a surprising level of intricacy. You can change the size and number of keys, and a few other things. The multi-touch integration is great as well.
Cons: Not the full featured one, but it’s free.
Get it? Sure, if you have kids that need to be entertained, or you like playing on a mini piano.