Couldn't find many reviews, but great features for a freebie. Worth a try, just for the comprehensive fatures that can only be found in paid apps
From the description - "Rockmate have been featured on Apple iPad TV ads.
Rockmate turns your iPad into a complete music studio that is easy and super fun to use"
Video of a demo can be seen at http://vimeo.com/fingerlab
Thanks Op, for some reason seeing the screenshot gave me a good laugh, seems like an interesting concept.