Hi, firstly great job on the app - really nice. I tried to do the demo puzzle on my touchscreen laptop, but while the dragging worked very nicely, I wasn't sure how to actually rotate the pieces myself (seemed to happen randomly when tapping the piece), would be nice to have a clearer way to interact, e.g. double tap to rotate 90 degrees.
Many have pointed out the auto rotation is either too easy or annoying, so I am considering alternatives. I originally started with single click to rotate 90deg but was told by early users it was too hard. Reconsidering ways to introduce this that is friendly to all users.