From there, you can click on the DEVICES tab to manage your devices. There are several things you can do here:
1) REMOVE devices by clicking the TRASHCAN symbol next to the device.
2) Click the PENCIL next to the device IDs to RENAME them. This device ID can be found in the HELP section of the Feeln app on your device, so you can make sure you're naming each device correctly.
3) ACTIVATE more devices by using the activation code box at the bottom of the screen. This is only valid for devices that issue you an activation code when you try to use them. When activating these devices, you can also name the devices at the same time.