You create a new device, under Devices, and then set this as the Device Type. Your custom Device Types usually show at the end of the list. Then when you first use the Thing on your IOS device, you’ll have to set the values for your Total Comfort login and Thermostat number (assigned by Honeywell, at the end of your URL when logged into Total Comfort website). Alternately, you can set these in the IDE after you create your device and re-look at it, after clicking it in the Devices list of the IDE.
[Also, you apparently set the Device Network ID, when defining the new device to the hex conversion of its IP address. You can find online IP-to-hex converters. I don’t know if this really matters, since the code never seems to talk to the device itself. Instead, it talks to the Honeywell TC website, which in turn talks to your thermostat.]