Ask HN: Paper form OCR options

I'm inheriting a process where people record numbers by hand in a grid and those numbers are later manually entered in on a computer. I'd like to figure out how to automate this to the greatest degree possible.

On the one hand, I could potentially farm this process out to Mechanical Turk. But, I feel like someone has probably developed some sort of paper form OCR app for this sort of purpose. I can even imagine some sort of clever number encoding / bubble filling sort of thing to reduce the error.

Does anyone know of such a thing, or better yet, have personal experience with a particular product? I feel like this is a machine learning business application that someone must have already capitalized on.

EDIT: The ideal workflow would involve snapping a picture of the filled form with a smart phone, perhaps with remediation of low confidence numbers right on the device.