I have owned the Moga Pro Power Bluetooth Game Controller for ages now and used it with loads of different android phones and tablets.
The setup procedure is meant to be as follows. Download the Moga app in the Google Play Store. Go into the Moga app settings and follow the connection setup procedure.
Just one problem, this no longer works and judging by the app comments in the Google Play Store, loads of people cannot get it to connect.
Well good news there is a way to get both Mode A and Mode B working. The trick is not to use the Moga app but you still should install it. So head over to the S7’s setting app. Select bluetooth. Scan. Make sure the Moga Pro is first turned to Mode A. It should show connected after a short while. If it doesn’t scan again, and again if necessary. It will connect. Also, press the button on the game controller next to the LED indicator light. This is top left. Once the S7 shows it as paired, slide the Mode switch on the controller to B and repeat the process. It doesn’t always pair on the first attempt, so keep trying. It took me about 3 attempts on each mode.
When connected and playing you will get a green icon in the status bar.