I have owned the SPH DA 100 app radio for a few years and its been fairly good to me, up until the apps tab remaining greyed out once my iPhone 6 is connected.
It has been connected like this and worked flawlessly up until now...
(top left)
I have spent a good amount of time searching for any ideas to what it could be, troubleshooting, eg, disconnecting everything, HDMI, wiring harness, lightning adaptor, USB to lightening iphone cable, ariels ect, and re connecting it back up, re installing app radio, switching phone on and off, re-setting the head unit its self under settings,