These include turning off the check engine light, reading trouble codes, and displaying the engine RPM. The FIXD is a professional OBDII scan tool app that easily completes all the basic functions that you’d expect from a dedicated car scanner. The FIXD adapter is bought separately but carries a very affordable price tag. The app has to be paired up with a FIXD adapter that slots straight into your vehicle’s OBD2 port. Best Compatible Adapter: FIXD OBD2 Scanner for iPhone / AndroidįIXD OBD2 is a free diagnostic scanning app that is available across iOS and Android devices.For Operating Systems: iOS (iPhone, iPad), Android.