Access is provided to a variable data printing app and a code detection app on a computer server. The variable data printing app is adapted to add machine-readable code to printable items and create a decoder app capable of decoding the machine-readable code. The code detection app is adapted to receive user identification information and transmit the user identification information to designer devices. The printable items are printed as printed products. The designer devices validate a user device based on the validity of the user identification information. In response, the variable data printing app is adapted to transmit the decoder app to validated user devices. The code detection app, operating on the user device, is adapted to decode the machine-readable code in user-acquired images into an optional secure link with the designer devices.