Your own mobile is your room key.
As soon as you have checked in with us you will receive a link on your phone with which you can activate the room key. This remains active during your stay and expires automatically afterwards. So it is no longer necessary to hand in keys.
You do NOT need to download and / or install anything for this.
In addition to your room, you will also have access to the main entrance door of the hotel. The main entrance is also the night entrance. You can share the key with your travel companion.