I installed a $25 Blue Elf WiFi camera under the roof on the back of the Pioneer. Ran 12V power back to it from a switch on the dash. When you power the camera up, it broadcasts it's SSID (like a home wireless access point) and the tablet can connect directly to it.
I have a Samsung Galaxy Tab A 10.7" tablet in a RAM mount on the ROPS that I run Agama Car Launcher 'dashboard' on. Agama is typically used as a 'front end' for double DIN car stereos that run Android, but clearly can work on an Android tablet or phone, too.
I've customized Agama so that all my various software is available from it (e.g., Lifetime Trailmaps, music player, etc.). One of the apps is the software for the backup camera.
So if I need the backup camera, I just flip the dash switch to power the camera and open the camera app on the tablet. The tablet is set up to automatically reconnect to the camera via WiFi SSID. When it does, you'll see what's behind you:
There's a couple second delay between hitting the power switch and the camera being ready to accept the connection from the tablet, but not too bad.
I thought about powering the camera from the reverse backup light circuit but figured that would NOT be a good idea if I had to switch between reverse and forward several times while backing up -- the power would get cut off whenever you shift out of reverse, so I'd have to wait a few seconds after shifting into reverse each time. Hence, the manual switch.
Link to
Agama Car Launcher software
Link to
Blue Elf WiFi camera