Brickit: Rebuild your Lego
brickit.app
What Jamie wrote
The idea here is fabulous. Use your phone, scan a pile of LEGO, and be presented with options of things to build. We've tried it and the scanning gets a lot right but also gets a lot wrong. I expect it will improve with use. The ideas are great no matter what. And if the scan got a piece wrong it is usually easy enough to substitute a different LEGO.