openMSX is an open-source emulator of the MSX home computer system that runs on the Android platform. It comes with a minimal firmware ROM known as c-bios that enables users to run most cartridge-based MSX games. To run a game, users can copy a dump of the cartridge onto the storage memory of their Android device and then insert the so-called ROM into the virtual cartridge slot of the emulator using the on-screen menu that can be opened with the standard Android menu key.

openMSX also allows users to install the firmware of their real MSX into the emulator, which enables them to play around with MSX Basic and all other features provided by the standard MSX firmware. For advanced users, there is a user manual available that provides an overview of the emulator's advanced features.

Overall, openMSX is a great emulator for those who want to relive the MSX experience on their Android devices.