Video players(QuickTime Player, MPV, MPlayerX, VLC, Mac Blu-ray Player, iTunes Music etc.):
swipe left/right: Previous/Next movie
swipe up/down: sound volume decrease/increase
rotate: fast or move forward/backward. I wish this could be as smooth as two fingers in touch pad
Browsers(Chrome, Safari, Firefox, etc.) and text editors(Sublime text etc):
swipe left/right: Previous/Next tab
swipe up/down: page up/down
rotate: scroll up/down. I wish this could be as smooth as two fingers up/down in touch pad(or like a mouse scroll)
Video editors(Final Cut Pro, iMovie etc):
rotate: that's most important. I think a scroll action is OK. in editor settings, rotate can scroll the setting line. In time line, just scroll left/right.
Photo editors(Aperture, Lightroom, Photos, Photoshop etc):
rotate: scroll the editor settings(I mean when focus on brightness, then rotate to decrease/increase the brightness). When in photo library, rotate can change selection through the library.
swipe left/right: select previous/next photo
swipe up/down: size in/out the photo
From a customer: