Mobile Gauges DUO variant application helps you to choose between different display variants:

black gauges style (default)
white gauges style

Also new add ons for selecting measurement units for:
GPS speed : km/h(default) or knots
fuel consumption : l/h(default) or gal/h
temperature: Celsius(default) or Fahrenheit

You have to enable bluetooth access and GPS speed to use all the features of this application.

Known errors:
1. if there is no MMDG device connected and you try to connect to an unrecognised bluetooth device, the app will end. You need to stop the app and restart app.
2. if you try to connect to an MMDG which is not connected to the engine, the app will retry to connect but because there is no data coming from MMDG it will refresh after few seconds.

As soon as connection is established correctly there is no known error. Please report in comments possible errors found.