This beat juggling app offers a simple approach to the crazy fluid style of MLR on PCs. Loops can be loaded to fill up an 8 or 16 step grid, and then played around with as slices. This allows for some really great grooves that are much more fluid than simple step sequencing, as you can mash things up on a whim. Audio Paste is still not supported at this time, but is planned and should greatly increase the usefulness of this app. See a full review here.
Disclosure: I received my copy for review from Big Robot Studios.