Every time you start with a new version of Presence the name will start out being the name that you gave your device in your device settings. Also every time you have a new version you will get a new camera ( so it is best to delete the old one ).
You can Rename the Camera in Presence
Tap on the camera you want to rename. The camera needs to be online in order for you to connect with it.
Tap on the top 'Options' button. This will open up the array of options you have, including a field where you can rename it.