All keys that have access to your flat lock but do not belong to you are displayed on the Other keys screen. 

Keys that you can see are, for example:

• Any “master keys” with access.
• Any service and maintenance keys with (temporary) access.
• Any other keys which are not blocked but have access.
• Old keys. 
• Or, depending on the configuration, keys for another valid person.

Note: As an additional safety feature, the app notifies you of all external keys (maintenance key, master key, service key, other keys, etc.) that are used in your flat lock.