United have produced an iPhone app with a couple of games in it. The games are not to my taste, but I am sure some will find them entertaining. Cleverly, both games promote the main features of their 'options' program, such as extra legroom and missing the lines at check-in and security.
What is of interest is that once you have played with the game and it finishes, or you quit, you can enter your email address for an instant win.
And I have done it 6 days and have 2 free 10% discount certificates. Not a bad rate!
for the iTunes link to download the app.