United Airlines has updated its iOS app today to let users watch in-flight entertainment through an iPhone or iPad. Around 150 movies and 200 TV shows are available at launch. The content is delivered through a WiFi network and it does not look like you have to pay in order to get access to the service.
The United Airlines Android app does not have this feature yet, but it should be updated with this service within the year. You can also watch the content on a laptop through a browser or with a plugin.
This service has not been rolled out to all of United’s fleet yet. Eventually it will be added for every plane. It will be available first on: Airbus A319, Airbus A320, Boeing 747-400 and some 777-200 aircraft.