Looking for an API, pretrained model or some guidance on how to implement handwriting recognition of post it notes, handwritten paper notes etc. for a mobile app.
The canonical example of image recognition for AI is recognizing handwritten digits from the NIST dataset; you'll find it in most computer vision tutorials.
If you want to learn about rolling your own: https://towardsdatascience.com/classifying-mnist-digits-usin...
https://machinelearningmastery.com/handwritten-digit-recogni...
https://scikit-learn.org/stable/auto_examples/classification...
The only issue is that you'll have to find training data for letters. I'd be surprised if that didn't exist.
Also, Google has an API for recognizing handwriting: https://cloud.google.com/vision/docs/handwriting
I haven't used it, so I can't vouch for it one way or another. But that'd be a pretty easy way to go!