I use the software Transcribe! from Seventhstring a lot for practising or transcribe songs. When practicing new songs I often loop certain sections and slow them down and gradually speed them up again.
I thought it would be cool if I could control these functions with Helix and found out that i works pretty well. So I thought you might be interested in how to do it.
Anyway, here's the article with a video
How to use Line 6 Helix as MIDI Controller for Transcribe! http://dshowmusic.com/line-6-helix-as-midi-controller-for-transcribe/ Scroll down to the bottom of the article for the video!
Enjoy