Amazon.com Inc. has rolled out what could be a very useful feature, an app for iOS that will help you find the right  nut, bolt, washer or screw you’re looking for.

It’s called “Part Finder,” a feature you can find in the search bar when you’re in the Amazon app. The icon is a screw. Hit that and scan the part you are looking at, so it can be measured, and if everything works, you should be informed exactly what you are looking at.

Then you can head off to the hardware store and buy replacements. Amazon said it identifies about 100 types of fasteners, which “represents thousands, if not millions of parts.”

You will, however, have to take the part and place it on a white surface next to a penny, presumably to help scale the object. Then some tilting of the phone will have to be done until the camera is aligned correctly, something the app will tell you. You might also be asked for some additional information.

Although the app uses augmented reality technology, Part Finder actually employs computer vision technology. Does it work well? Early reviewers of the app have said it takes a bit of getting used to, or that it’s a great idea that just doesn’t work well enough.

For some reason, Amazon kept it quiet when the feature was released a few weeks back. The company did say, though, that Part Finder will find more things than just fasteners in the future, saying it will expand to all kinds of replacements. It’s only available for iOS right now and Amazon hasn’t said when it might come to Android.

Image: Sam-Cat via Flickr