New and existing GT Series customers now have the option to screen visitors and unlock doors directly from their smartphone. When connected to the GT-TLI-IP Mobile App Network Adaptor, the AiphoneGT App provides audio and video communication over WIFI, 3G, or 4G. The in-app slider makes it easy to unlock the door when a visitor is approved but is also designed to prevent accidental unlocking for a more secure apartment or business suite.