SynprezFM 2 is a versatile and programmable polyphonic synthesizer that comes with a multitouch dynamic keyboard, arpeggio, effects, and 1024 built-in instrument patches. It uses Frequency Modulation, a lightweight method for generating complex harmonic waveforms by mixing or combining sine samples controlled by envelops and LFO. This synthesizer is capable of producing analog style pads, emulating classic or modern instruments, or inventing new and awesome crystalline sounds. It also serves as a Yamaha DX7 emulator, allowing you to render sysex files with accuracy.

With SynprezFM 2, you can create and save your own patches by editing one of the unsorted built-in ones or starting from scratch with the 'init voice' function. You can also record WAV, connect a MIDI keyboard, and take advantage of a small step sequencer. Even small devices can now leverage two synthesizers thanks to an optimized layout. To simplify the classic usage, complex functions are now only available in 'expert mode' (activatable in the setup page): this regards the patch editor and the new micro-tuning feature.

While playing, you can trigger an after-touch vibrato effect by dragging your fingers on the active keys or shift the keyboard to different octaves. Other performance parameters can be accessed above the keyboard, including two types of portamento, a sensitivity range for pitch or volume modulations, and some effects that give a sense of depth when using a headset, especially on plucked sounds. You can also adjust the polyphony to adapt to your device capabilities. Thanks to an optimized core, you can hear up to 16 channels playing together, even on mid-range devices.

The latest version of SynprezFM 2 comes with several bug fixes, including countless annoying bugs, a pseudo compressor to enable louder sound, MIDI support based on Android libraries to address more MIDI controllers, and storage access rewritten to solve first-time access problems (and support Android 11+). It also features several evolutions, such as wireless Bluetooth MIDI support, "MIDI slave" support, support for multiple MIDI keyboards, finer volume and balance scale wired on MIDI, and a peak indicator on VU-meters. Additionally, it has drop-down menus with pseudo LCD, output volume operating after the FX processor, a description of the device capabilities in the configuration page, and better MIDI traces to diagnose problems.