GBF smart video doorbell system for 8 units apartment building is the most friendly installation intercom system, wiring is not necessary. It saves you lots of installation labor and cost. This smart intercom system supports two-way voice communication and remote door release functions. Unlock door with IOS/Android devices (Iphone, Ipad and other smart phones) or with your indoor monitor. You can watch, hear and speak to the person at your door and unlock the door with your smart phone or with your indoor monitor, no matter where you are or what you are doing. The application is available for IOS and android mobile phone and tablet. With WiFi/3G/4G connection, intercom and door release all remotely controlled by your smart phone or tablet no matter what your location is, even you are away from home. Meanwhile, Application and server service are all free to download for end users.