Fantastic, but a little room for improvement
Sudoku apps and sudoku solvers are a crowded space. This one differentiates by solving step-by-step, so you can learn and practice the techniques it uses. It works great, and has been super helpful to me. There is room for improvement: (1) if a puzzle requires too many steps to solve, the app will crash. Similarly, if it can't go from the entered clues to a final solution, it won't even accept the puzzle. I'd prefer if it took whatever puzzle I gave it without attempting to solve to the end, and then just solved the next step; (2) it would be great if it could enter puzzles from photos, not just the camera; (3) more techniques! Empty rectangles, more fish, etc. For me, chains and subset exclusions are a last resort - I'd like as many "logic only" techniques as possible first; (4) it would be amazing if techniques could be reordered and turned on and off for a particular puzzle; (5) app looks to be out of development. Active updates would be welcome. I would gladly pay for some of these features as in-app purchases. If the app adopted ads, I would delete it.