I've found two issues so far with the LiveJournal app for Android. First, SwiftKey is seriously disabled when using the LJ app. You can't do swipe or gesture typing, and the predictive bar completely disappears.
Second, you can't reply to comments. It's simply notan option. You can make additional comments, but you can't actually reply to a comment.
This may be connected to my recent upgrade to Android Lollipop. If so, there are apps that have worse problems with Lollipop. My Barnes and Noble Nook app is completely and absolutely broken under Lollipop, for example. I can't read any of the books that I paid for and downloaded. And Barnes and Noble isn't talking about when they'll fix it. They deserve to go out of business, but we don't deserve to have no alternative to Amazon.com!
Edit: it turns out that you canreply directly to a comment via the app. All you have to do is tap on the comment, and the reply will automatically open up. Not exactly obvious, and they should have added it in to the three dot menu as well. Still, at least it isan option.