App works with ELM Bluetooth device connecting to car's OBDII Port. Diagnostic features include: Collect, view & export up to 4 OBD2 PIDs. Read & clear present/pending DTC. Detect supported PIDs. Take & export OBD PIDs snapshot of your car. Speak out PID value. Vary rate of data. Create, show & export custom data stream. NOTE: 15min is Google's rule.