Now it just got upgraded with a new Synthesizer module called Silverbox and yes it is of course for creating 303 type of sounds. You better look at the video and get an idea,
then if you have not download the application that is for free and with no publicity.
It is also open source so you can get your programming hands on it and be part of the development or just modify it to your hearts content!
P.s- One of the comments that shows up on the Playstore is calling it "basically just a soundboard" that is a big lie...