I wouldn't have if it weren't for the video. I forgot for about a year, then cleared my drafts, found the one I made from the vid, and copied off that.
When 📱 Is pressed
Set (variable)Scroll2 to Last Touch Y
Increase Scroll by (number) x Last Touch Y - Scroll2
And then for an object at the middle at start, put
Set position to X 512 Y Scroll +384