You can create up to 8 variations, to add another one click on the + in the bottom right corner next to 1.
Use 1-8 keys on your keyboard to change between variations.
To change the tempo (BPM), click -/+ in the bottom left corner, or click directly on the number and use your keyboard.
You can change some instruments by clicking on the label. Try clicking MA to change Maraca to Clap.
Currently only Roland TR-808 is supported:
The Choke is the interaction between Closed Hi-Hat and Open Hi-Hat. When both Hats are placed on the same beat, the Open Hi-Hat is ignored and Closed Hi-Hat is played on both channels, as a shorter note. Experiment with it to add movement to your groove!
You can paste (CTRL+V) text representation of the pattern to import it. It doesn't have to be the full list of instruments, but the pasted pattern should always have 16 beats. Try this one:
CH X-X-X-XXX-XXX-XX
SD ---X-XX-----XXX-
BD XX------XX------
AC X-XX--X-X-X-X-X-