PPSSPP is the best, original and only PSP emulator for Android. It runs a lot of games, but depending on the power of your device all may not run at full speed.
Galaxy S7 is not currently supported, fix coming soon.
No games are included with this download. Dump your own real PSP games and turn them into .ISO or .CSO files, or simply play free homebrew games, which are available online. Put those in /PSP/GAME on your SD card / USB storage.
Some games that work
– Persona 2, Persona 3 Portable
– Dragon Ball Z
– Little Big Planet
– Burnout Legends, Burnout Dominator
– Final Fantasy : Crisis Core
– Final Fantasy : Type-0
– Monster Hunter 2 Unite and 3: HD Remake
– Soul Calibur
– Tekken: Dark Resurrection and Tekken 6
– Grand Theft Auto LCS / VCS
– and many more…
See http://www.ppsspp.org for more information.