Hi
Roastmaster's data structure is a bit too complex for the usual iCloud sync. In lieu of that, I've provided a few different ways to quickly transfer data to and from other devices. The easiest is to open the drum door on the home screen and choose "Export Current Database". If your other device is awake and nearby, you should see it appear in the "Airdrop" section. Tap it to send it to that device, and choose "Overwrite" on the receiving device.
Hope this helps.