I use an iPhone 5 and mine is doing the same thing. It's been mostly in the past two days. Sometimes I'll get lucky and load a topic, but about 90% of the time, it crashes.
I work tech support for mobile phones. Power cycles, system software updates, and uninstalling/reinstalling doesn't appear to solve the problem. It's got to be a software issue.
Everybody is a genius. But if you judge a fish by its ability to climb a tree, it will live its whole life believing that it is stupid. - attributed to Albert Einstein