PS4:Emulators and Homebrew Games

While RetroArch covers most bases when it comes to emulation, you have the option to install standalone emulators listed below. There are two main types of emulators: XEX and ELF emulators. Keep in mind that ones that sound "too good to be true" likely will run very poorly on the system.

Native

 * mGBA (Game Boy Advance)
 * PCSX-R (PS1)
 * GBemu (Game Boy / Game Boy Color)
 * Cinoop (Game Boy / Game Boy Color)
 * PS4NES (NES)
 * PNES (NES)
 * Reicast (Dreamcast)
 * Yabause (Saturn)
 * fMSX (MSX)
 * Chip8 (CHIP8)
 * OpenBOR (Open Beats of Rage engine)

Via PSP Package
SMSPlus (Master System)

Via PS2 Package
SNESStation (Super Nintendo) FCEUX (NES) DOSBox (MS-DOS)

Via RetroArch for PS2
ReGBA (Game Boy Advance) DaedalusX64 (Nintendo 64) QuickNES (NES) PicoDrive (Genesis / Master System) PGEN (Genesis)

Homebrew Games

 * Lapy Game Collection
 * River Raid by Lapy
 * Console Wars by Lapy
 * Brain Splitter by Lapy
 * Nanospeed Gamer by Lapy
 * PS4 Doom ps4 port of DOOM
 * PS4 Snake ps4 port of Snake
 * PS4 Pacman ps4 port of Pac-Man
 * ShepHard by MasterTurkey
 * The Enchanted Forrest by RetroGamer74