NGP.emu is a Neogeo Pocket Color (NPC) emulator based on Mednafen/Neopop. The app is designed to be as simple to use as possible. 

There are a lot of settings to customize the appearance of the game. It supports a wide variety of devices from the original Xperia Play to modern devices like the Nvidia Shield and Pixel phones. You can configure the on-screen controls and the audio and video settings. In addition, you can play in either the English or Japanese game language.

The app has been designed to run as fast as possible and uses the device's hardware to help it achieve that.