Hi Brian,
This isn't a MIDI device that sends piano MIDI keyboard notes, but a Bluetooth device that sends computer keyboard (QWERTY, arrow up/down/etc.) keystrokes. This is why it won't show up as a MIDI device. It looks almost identical to the Lekato page turner that I know works.
Basically you connect the device over Bluetooth to your Android device, then open up OpenSongApp and after you configure the foot pedal commands, it will just work.
Check out this page of the manual (and definitely also watch the short video embedded) to set up your pedal as desired. You may find, bizarrely, that this pedal sometimes works better when it is switched to iOS mode rather than Android - try them both to find out which works best for you.
P.S. Let me know how you get on and if the pedal works, I'll add it to the known working pedals. I'd also be interested to know if the long press actions work (you may have to switch on AirTurn mode on the app foot pedals page for this foot pedal to simulate long presses).
Best wishes,
Gareth