It is basically just a standard step sequencer which can be used to prototype beats. It comes with 70 included sound samples; each that can be adjusted by two octaves (one up, one down.). There are seven available channels to edit, and you can use 16 to 128 steps in a composition.
In addition to the sample playback, there is also "synth mode". For each channel you can use a three oscillator synthesizer to generate sounds. It comes with 12 selectable waveforms, an LFO, amplitude settings, and a lowpass filter. There is also a "unison" mode that you can use that will automatically use three detuned waveforms. This is available per each of the waveforms, so you can actually have nine concurrent waveforms playing per synthesizer. Here are a few screenshot so you can get an idea of what the app looks like:
Also, please note all the features mentioned are all part of the free version. And here are the links to the app on the app stores if you'd like to check it out:
Android Market
Windows Phone Marketplace
Windows 8
Again, if you find any bugs, have any questions for use of the app, or have any ideas for new features, please let me know.
Thanks!