Many of the apps don't work properly with the iPhone 5S and iOS7. For example, gMusic and gMusic2 don't recognize the Pioneer unit anymore, Stezza won't scroll through lists, EC Touch crashes when you try to use their various built in apps, Mixtrax doesn't recognize iTunes Match music, making it useless for me, and Motion-X GPS Drive doesn't recognize the Pioneer unit. Pandora hasn't worked since the firmware upgrade last spring ... it hangs when you search for your stations.
There seem to be as many apps which don't work as do. I assume that this all happened with the iPhone 5 and iOS7,so hopefully they'll be fixed.
The ECTouch people sent me a beta to address this issue, but it crashed just like their AppStore release.
However, WAZE works perfectly, which is the app I really want to use, so I am happy.