Add device

You can add a new device by clicking on the little triangle at the top left corner of each grey box.

Remove device

You can remove a device by clicking on the little triangle at the top left corner of each grey box and select 'remove'.

It is possible to do so for your local peer and all the joined peers, unless remote user locked the peer for remote manipulation by clicking on the lock-symbol and thus switching the locked status of the local peer.