The new feature in United’s mobile app lets you set your seating preferences so you’ll be notified if the one you like becomes available. United began rolling out the option Friday.

“We want to ensure that our customers are equipped with the best mobile tools to make their travel more convenient,” he said. “In addition to United’s iPhone, Android and Blackberry ...

Mobile boarding passes are accepted at 101 airports worldwide on United and Continental flights. The app also lets users get real-time results for flight statuses and view interactive airport maps.