ReceiptChain

One of the cool things you can do with this is message the owner of a product based on it's QR code. If you print out the QR code and put it on your product people can send you messages without knowing your email or phone number. The message will be routed to the current owner in the app. It's also a convenient place to keep records for all your things at home. You can keep them public or private. Then when you get rid of your item you can give the records to the next owner so nothing is lost.