Earlier this year I thought it would be interesting/fun trying to build an art filter that transforms photos into impressionistic paintings without using any ML

Earlier this year I thought it would be interesting/fun trying to build an art filter that transforms photos into impressionistic paintings without using any ML/neural nets like a lot of apps do these days, but instead just use vector calculus, randomness, and drawing each brushstroke at a time. Tinkered with a Python version for a few months then ended up converting it to C/C++/Objective-C to make an iOS app out of it. Released the iOS app earlier this summer under the name PaintSnap but I'm still tweaking the painting algorithm every week. Not the most utilitarian app but it was fun building it and tinkering with the algorithm.