Sonarworks True-Fi app - can you use it for synths etc?

[Liney]

I'm a big fan of Sonarworks Reference 4 software for my iMac, as I do most of my mixing on headphones. I've noticed that they've developed an app, which immediately piqued my interest.

Am I right in thinking though that you can only use it to listen to Spotify and your music library etc, and not for Garageband or other standalone synth apps? If that's the case it's a shame because it would be great to use them for sound design on the ipad, but I suspect that it may be a limitation imposed by Apples iOS, whereby you can't get all audio to go through one app (just a guess though, I may be wrong).