Earlier this month, Amazon rolled out a new feature on it's app. Take a picture of a screw or washer and it will help you find and order an identical match. The feature asks you to place the (for instance) screw on a white piece of paper and place a penny next to it for scale.
Snap a pic, and the search engine takes it from there. It'll let you customize your search to narrow down the results too. Slot head or phillips head, brass or galvanized, US or metric. This feature is helpful both for professionals and hobbyists.
Whether you're working on your car or a cabinet, fixing the deck or fixing a broken toy...the Part Finder feature on the Amazon app is sure to come in handy.
So far, iOS only.