Please make sure that all your devices on which you use myatmo are registered under the same Apple ID as the device on which your myatmo Premium subscription was purchased. If this is not the case, a myatmo Premium subscription will be moved (!) from one device to another if you want to use it on multiple devices. This means that the Premium subscription will be deactivated on one device and activated on the other.

All your devices must display the same Device ID at the bottom of the myatmo Premium purchase screen. If different Device IDs are displayed for each of your devices, then your devices use different iCloud accounts and it is not possible to use myamto Premium on all devices in such cases. Please refer to this FAQ.