I have twice installed and attempted to use the plugin – and both versions. In each, I am using Verizon phones. I can log in and see all of my devices on my iCloud Account. So I know the passwords and username are correct. However, in each case, the App returns an error logging into iCloud and no devices (probably because the login didn’t work). Help!
Start by turning on Debug in the interface and post your LuaUPnP.log file content (the relevant stuff for the iPhone Locator plugin, please) here.
We’ll see what the Debug output shows and perhaps we can help.