base function intoduction:
1. view up to 16 live video streams
2. device management
3. device push notification settings
4. Record and playback video
5. Landscape and portrait orientation support
6. using QRcode to add new device
base function intoduction:
1. view up to 16 live video streams
2. device management
3. device push notification settings
4. Record and playback video
5. Landscape and portrait orientation support
6. using QRcode to add new device