A free app for Android, by djdron.

USP – ZX Spectrum Emulator is a free software that allows you to play ZX Spectrum games on your computer. It’s a portable version of the ZX Spectrum emulator that has been compiled for Windows, Linux, Mac, and Android.

The app is based on a native port of the ZX Spectrum to the Android platform. It can play games in the following formats: sna, z80, szx, rzx, tap, tzx, csw, trd, scl, fdi, td0, udi, zip.

There are several ways to start the emulator. The most convenient way is to start it from the desktop. You can also start the emulator directly from the Android device, or start it from the command line.