I think I've determined two possible sources of the crashing, both related to the change to display margins in iOS 10.3:
The site I read Fanfiction at, Fanfiction.net, has added an animated advertisement on several of it's pages. This ad interferes with the app in several ways, one of them being any drop-down menus are immediately closed while the ad is playing.
As I stated earlier, iOS 10.3 changed the display margins for page views, which caused a significant number of apps to not function properly until they were updated.