Can I add multiple devices to the app at the same time or do I have to add them one at a time?

Each time you add a device the system will scan for all available devices and add any that it finds, regardless of type. This way you can comission a whole house system at once. In some cases where there are a lot of devices or they are widely spread you may need to scan twice to find them all as a single scan will time-out before all are found. Be aware that the smart lamps will only remain in pairing mode for 3 minutes, so it is best to switch them on at the mains just before beginning comissioning. The bridges and smart plugs will remain in pairing mode until they are found by the app.