Understanding Top Row icons on home screen

I have Ultraloc Pro Wifi running on iOS. The top row of my device home screen I have 4 large icons ‘Security’, ‘Power’, ‘Lock’, ‘Light’. I only have a lock installed. What does it mean when the ‘Lock’ button is highlighted or not?.

Also, Is there a detail/complete user guide anywhere for the iphone app?

@Robert33 Hi Robert, when the “Lock” button at the top is highlighted, it indicates that all the smart locks under the current address are filtered. Thank you!