In terms of someone hacking the system, not for himself, but for the benefit of the people, there's this guy Edward, with a documentary made about him called 'CitizenFour' (2014). It's pretty good! It doesn't end like 'The Founder' though.
In terms of continuously hacking an invention to find new ways of exploiting it, I'd say the hard sci-fi indie movie 'Primer' (2004) pretty much revolves around that (although it might not be completely obvious during the first viewing).
I have to mention 'Spin' (1995), about the 1992 US election candidates. The hack here is not really the subject, but the documentary itself: it is entirely made of unauthorized satellite feeds of pre- and post-interview scenes not meant to be broadcast, i.e. you see all politicians talking unfiltered and off-the-record, as they were all unaware that, even though they were not being broadcast at those very moments, the cameras were still on and transmitting over satellite -- and their feed could be easily intercepted.
Rant on actual/software hacking movies: it might be different for some other medium, but I don't know of any movie that depicts hacking in a realistic way and is a decent movie. In my opinion, this is because there is nothing cinematic in hacking. As far as I know, the only one that marketed itself as 'realistic' on this topic was 'Blackhat', but that aspect of the movie was boring, and almost everything else was lazy and/or dumb. Maybe something on TV?