When typing a question/answer on the site, we get this nice bar above the input box:
It helps do quick things like format code and whatnot. As it stands, there's nothing like that on the iOS app. For some things, it's not a huge deal. If I really want to, I can hit the space bar a bunch of times and get what I need (though who would want to write that much code on their iPhone is beyond me). Where the real problem comes in is with things like the ` (back tic) key. There isn't one on the iOS keyboard and (at least without jailbreaking) I don't know of a workaround to make this work.
To be fair, this problem isn't just for the iOS app. This is also a problem when I'm using the regular site, but it's become more of an issue since I'm more likely to respond now that I have a specific app. Can we get some sort of augmentation for the default keyboard?