Individual / private solution free version:
Receiving video calls, video before answering, opening up to 2 doors, viewing cameras, screenshots, favorites. Work within the network. The application does not need to be in memory. Video comes from 2 to 10 seconds (depends on phone, Internet and Android version). When using the SIP server True IP mini and white IP addresses, push notifications are activated to receive calls in 3G / 4G, the video comes up to 2 seconds.

Multi-apartment solution with paid licenses: