On sale for $9.99, regular price is $50!! https://itunes.apple.com/us/app/dashcommand-obd-ii-gauge-dashboards/id321293183?mt=8&ign-mpt=uo%3D4
I use a wireless adapter; for iOS make sure it connects through WIFI. Just like this one: ELM 327 Wi-Fi OBDII
I just bought the same. I have a bluetooth one that I use now with my Nexus 7 tablet. I'd rather use an old iphone, which doesn't support bluetooth for OBD2.