DashMaker lets you write plugins with full access to your vehicle OBD as well as the full power of the LUA programming language (great documentation online).
If you are interested in developing your own plugin then you can find out how to get started here:
Full information on building DashMaker apks on Google Play is available here:
Note: This plugin needs the full version of DashMaker
Startup Tester for DashMaker
This app has access to :