United will now let you join standby lists for earlier flights through its mobile app

United’s mobile app now lets passengers add themselves to standby lists for up to three earlier flights to the same destination after being re-booked, with automatic monitoring and text alerts when seats open. The airline will not cancel the confirmed reservation until the traveler opts to switch, extending its self-service recovery tools that already include real-time aircraft status, TSA wait-time tracking, and luggage location sharing.