United Airlines is updating its iOS and Android mobile apps with several new features, including estimated security wait times to give travelers a better idea of when they should arrive at the airport. The move comes as the ongoing partial government shutdown has left TSA checkpoints understaffed. In the “Travel” section of the United mobile app, travelers can now view security wait times for the airline’s U.S. hub airports in Chicago, Denver, Houston, Los Angeles, New York/Newark, San