Smule's latest app is called MadPad. It's somewhat similar to Harmonix's VidRhythm in that you can take regular everyday sounds and turn them into music. But instead of combining sounds into a premade video, the app will turn sounds into different parts of an instrument, which you can then play with impunity. You can mix your own sets or use a series of premade sets from various musicians. You can use the created instrument to make songs or share sets on Twitter, Facebook, or over email.
Smule has created a quality app here, and while it's not quite as easy as VidRhythm, in the hands of capable musicians, MadPad can make something special. It's available on the iPhone for 99 cents or in HD on the iPad for $2.99.