Sketch 2 Code - Turn hand-drawn design into a HTML with AI. By Microsoft.
Vectorizer.io - Fast and easy way to vectorize an image online
PaintCode - PaintCode is a unique vector drawing app that generates Objective-C or Swift code in real time, acting as a bridge between developers and graphic designers.
Autotracer.org - Free online image vectorizer
Schwartz - Very similar to paintcode but costs wayyy less
potrace - Open source program that transforms bitmaps into vector graphics.