ARC Browser
ARC Browser is a rom collection browser and emulator frontend that maintains a database of all your games, presented in a user friendly way, and let's you play them using your favorite emulators.

Suitable for both phones and tablets (gamepad recommended), Android-powered arcade cabinets and of course Android TV!

Get it on Google Play
Known issue: RetroArch can't access config file on Android 11 or above
Issue: When launching games in RetroArch from ARC Browser on Android 11 or above, you get an error message in RetroArch saying it can't access the config file, and controller input and other things might not work correctly

Workaround/fix: Go to the system's settings in ARC Browser and go to Emulator extras. If the CONFIGFILE parameter there starts with "/mnt/sdcard/Android/..." try changing it to "/storage/emulated/0/Android/...". Note that this path may not be correct for everyone, you might need to figure out where your RetroArch config file is and enter it here.

Note: This is fixed in the templates, so it should only affect already configured systems when upgrading to Android 11.
Known issue: Can't select mounted NAS directories when selecting ROM directory
Issue: When browsing for a ROM directory in ARC Browser, mounted NAS directories on the device do not show up in the list

Workaround/fix: When editing the ROM directory in the system's settings in ARC Browser, manually type "/storage/servername" (for example, if the NAS server is called OMEGA, type "/storage/OMEGA"). Then press Browse and you should be able to see the shared directories.

(this is probably only relevant for the Nvidia Shield)
Known issue: Android 11
Issue: You upgraded to Android 11 or above and now everything is broken

Workaround/fix: See this page for more information on how to get things up and running again.