[RobinD42]

I think mainly because it is simply not expecting html in the description text because the professionally made EPUBs I've seen (downloaded from places like feedbooks, etc.) all seem to have plain text with no html tags. For example in the attached screenshot the first book shown is one I converted with Calibre and does have a description that is not shown, (except for the leading <), and the second was downloaded from feedbooks. Other android readers I've tried also do not seem to expect html tags in the description text and simply display the raw text with the tags visible.

But I am talking with the developer about another issue so I'll bring this up too. But like I said, it's not just this one application, but at least a few of the more common ones that I've experimented with.

Edit: I've added an additional screenshot from a different book reader.