This suite of six MIDI sequencer tools run as AU-only plug-ins within a suitable AU-host. Rozeta also makes use of one of the new features Apple has snuck rather quietly into the iOS 11 update: the ability for AU plug-ins to send MIDI Out data.
Slicing audio samples based upon transient detection is a well-established technology, however, VirSyn have added two very interesting further twists that up the ante considerably in creative terms...