Torque is an engine diagnostics application for Android that allows you to directly monitor your car engine control unit (ECU) and retrieve various information from the sensors connected to it.
It uses a cheap ELM327 based Bluetooth to OBD interface adapter that is readily available on eBay. It should also work with the PLX devices Wi-Fi OBD adapter provided you apply the relevant rooting and Ad-Hoc hacks to your device to allow you to connect to the Wi-Fi adapter in Ad-Hoc mode.
*Shows / resets fault codes
*Can export log files to Google Earth / CSV
*Live data display