FPse for Android is the fastest and most compatible PSone emulator for handheld devices.(also known as PSX or Playstation 1)
More than 150.000 active users and rated up to 4,5 stars on google play!
FPse support OpenGL which gives outstanding graphics!
Take a look to the Official Documentation to understand requirements and how it works:
Create an ISO image from your favorite games and enjoy playing them on your Android phone.
High sound quality
Real-time save states
Audio track emulation (using .cue files)
Dynamically loadable Overlay Pads
Analog Stick emulation
Compatible with G-Sensor, Touchscreen and Hardware keys
Supports .img, .iso, .bin, .cue, .nrg , .mdf and .Z disc image formats
Full Support for IcontrolPAD, BGP100,Zeemote (via Bluez IME)
OpenGL support via external plugin!
FPse for Android