The dice+ used to sell a developer kit. That was a dice with a firmware that was used for developing applications(you didn’t need a public key for each application to be able to connect to the dice).
To be able to use the consumer version of the dice+ for developing you need:
1) http://developers.dicepl.us/show/download - download the new firmware and the firmware uploader software for your OS 2) you need to put the dice into the restart mode. You need to connect the dice, immediatly disconnect, then connect it back. This should be done really quickly for the dice to enter the state where it would accept new firmware. It will start blinking in white color. 3) connect to dice+ (button in software on windows) 4) browse to “open firmware file” 5) upgrade firmware