NEMp3 is a download payment web app, utilising the NEM API to combine unique customer IDs with purchases, published to the NEM blockchain. These IDs can be retrieved at a later date to be used as proof of purchase, before serving a download. No customer information is stored by the app; the linking of purchases to downloads relies wholly on the blockchain as a payment ledger.
The app currently uses SHA256 hashed email addresses to provide unique ID strings for each customer. Assuming customers use the same email address at a later date, their IDs will remain consistent, allowing for records of their payments to be retrieved from the blockchain. Payments can be made either by scanning a QR code with the NEM Wallet phone app, which automatically includes the customer ID in the payment message field, or by manually entering payment data using the Nanowallet app. The total sum of these payments are compared against a price set in the app, and a download button is served depending on whether the payment price has been met or not. Downloads are currently served via Amazon S3 servers, using securely signed download links.