Iphone Pro Studio Music Recording Ap

Does anyone have any information about pro studio music recording ap for the Iphone. In the Itunes ap store the description reads as if you can import a track from the library and record yourself . It is a paid ap I think the cost is $10. I'm sure the ap doesn't have all the functionality of Garage Band but could still be useful. The recordings are in AAC mp4 format, and can be emailed from the ap. Any information would be greatly appreciated This ap could be convenient for practice if the description is accurate when you think you got that chorus down, import the track and record yourself.