1 star now; 5 stars a couple years ago
Used to be a neat app, but at some point the default sample rate on my iPad and iPhone was switched from 44.1 to 48 (I have to assume as part of an update, was nothing I did manually), and since then Solo has not worked, despite following directions to change the sample rate back to 44.1. Paid for the full version way-back-when, but is now seemingly DOA. Shame, was really cool, and all other sound apps by this developer are amazing.