Book flights & check-in with the Frontier app to save time and money! Travel is easier than ever before with the Frontier Airlines mobile app. - Book your next trip, search flights, and explore our route map and destinations - View and manage upcoming trips - Upgrade your seat to UpFront Plus, Premium or Preferred, or select a standard seat - Add a carry-on bag, checked bag, bundle, priority boarding or other options - Check flight status, including departure time, arrival time and gate informa