The plot: Gerard Butler is a secret service agent on the President's detail who gets into the doghouse by doing his job properly, with unfortunate consequences. Some time later, Koreans storm the Whitehouse in a cunning plan, and Butler - now exiled to the Treasury Dept across the street - is the only one who is in a position to fight back.
Oh, basically it's Die Hard in the Whitehouse.
I have no idea whether it's any good, since I only made out a handful of lines of dialogue, despite the iPad being on full volume, and Apple's dreadful movie app didn't appear to have subtitles for this film. So mainly I was working out the plot based on the facial features.