Hello, I'm the author of ProSudoku. This is a project I've been working on for a few months (mostly as a lockdown project to keep me busy).<p>This project has been a journey for me, and I've learned a lot about how sudoku puzzles are created, graded, and solved. I learned about the solving techniques that pros use to solve hard puzzles and I've incorporated them into a step-by-step solver that explains to the player why a move is legal.<p>I have also implemented my own handwriting recognition model using Apple's turicreate and the EMNIST dataset. The main reason I trained my own model is because I wanted to use the X character as a way to erase numbers, and also because I want to be able to add scratching over a number to clear it (I just need a dataset for that, which I'm working on).<p>The handwriting recognition also supports inserting pencil notes, and clearing them.<p>Overall I've had lots of fun working on this, and I hope you can give it a try and let me know what you think. I am already working on improvements, and so feedback will be extremely helpful in making it better.