We're aware of a number of issues with Symphonix Evolution on iOS 7. In particular, users will see a message on startup about Audiobus initialization failing due to Apple's tighter sandbox rules and improved OS security (it's taken us a little while to find a solution that works reliably). The good news is that these problems have now been resolved by our development team and we'll be submitting the update to Apple for review in the next day or two.
In the meantime if you've not updated to iOS 7 yet and are using Symphonix Evolution, you might want to wait until our Version 2.1 is released.
I'll update this blog soon with more information about our new version!