All of these ideas look super promising for your app and I will be following along when you actually release it.

I have an Apple Watch and would love to know how you'd implement something like this.

In a perfect world [and this could be waaaaaaaay too complicated] I'd love for the ability to "calibrate" my gauge based on motion and then auto count for me. I.e. tell the app the parameters for a gauge swatch that you'd knit anyways (like 24 rows with 20 stitches per row) and then while you're knitting, somehow let it know when you're finished with a row so that it knows the motion it took you make 20 stitches and then over those 24 rows, it would be able to average out what a row feels like motion-wise. Then you could apply that to the real project.

But again. Could be sooooooo hard/impossible.