I use Avare on my Android device and use a suction mount holder that positions it at the same height as my glare shield, just to the right of my whiskey compass. I recently found an Android app called ixGyro that uses the device GPS signals as well as the onboard accelerometer and gyroscope to provide a real time digital Attitude Indicator as well as heading and speed indications. I haven't tested it in the air yet, but it seems to be a pretty robust app and may be suitable for a backup in an emergency. Has anyone else tried it? I'm using the free version - there is a pay version with more features.