Ludo: Minimalist Emulator Frontend by Libretro (RetroArch)
Libretro, the makers of RetroArch, have released a minimalist emulator frontend for PC and Raspberry Pi 2 & 3 called Ludo. It is also available as an OS, called LudOS, which is tailored for TV Boxes. Ludo will be similar to RetroArch but with less features. https://ludo.libretro.com/