I'm currently developing a MIDI controlled VST3 / AU Looper plugin tentatively called SketchPad. I'm making it free for MIDI Expression customers. Although it has already been extensively tested on my end, I think it's fair to say that this is still BETA software. Questions and feedback are very welcome.
Download
https://www.audiofront.net/downloads.php
If you are a MIDI Expression owner, you can get a free license here
You can get more information by reading the manual.