I've been working hard to improve the performance of StitchSketch.
So far, I rewrote the internal drawing engine, and it seems to be much faster than before. Overall, it is about five(5) to ten(10) times faster to draw screen.
I also changed look & feel, and added some features.
Anyway, it will takes a little more time, so please be patient!
So, it is possible and easier to implement layers, vector graphics (back stitches), etc., well in the future.