I must be blind because I can't see any blurriness inside e-books themselves in Marvin on iPad Pro. Well, good for me, I guess.
As to Marvin's development, I'm afraid Kris may have lost interest in Marvin.
I consider Marvin an unfinished product – the non-working syncing of annotations being the most glaring omission to me.
Well, it speaks volumes when the best iOS reading app is one that is unfinished. We live in the age of Barbarians; you just can't expect quality, because you most likely aren't going to get it. Just lower your expectations as much as you can, and you might get a pleasant surprise every now and then.
Marvin, even with all its shortcomings (that it appears are here to stay), is miles better than Stanza ever was, or dumb, always functionally limited corporate software like iBooks and Kindle ever will be. That's good enough for me, given my suitably lowered expectations.
Here's my theory: Kris is simply creating software for his personal use, and is so generous as to share the results of his work with the rest of us basically for free. Given the minuscule prices for which iOS apps are sold, I don't think an independent developer like Kris can ever make a decent living by developing iOS apps. So, he appears to be creating apps primarily for his personal needs, and that's understandable. He appears to be content with Marvin's current status and functionality, so he basically stopped developing it, and he moved on to other apps that he finds useful for himself, such as the journaling app Gerty (something I don't need, because I already use Day One) and the mail app Sift (something I don't need, because I already use Mailbox). In order for me to be interested in Gerty and Sift, they'd have to be superior compared to Day One and Mailbox, but they are not – their feature set, for one thing, is limited compared to those, just to name the first obvious hurdle to their use. By the way, ever since Dropbox purchased Mailbox, that software has markedly deteriorated, and now they no longer even
pretend to be resolving bugs and further developing the app. As soon as a corporation touches a piece of software, that's basically the death of it. Corporate software is, by definition and necessity, stupid. Look at how enormously stupid the entire iOS, as well as other Apple software is. They just can't help it. Being as dumb and functionally limited as they can possibly get away with, is their corporate philosophy. The only rescue can be brought by third-party independent developers, typically humble folks like Kris, so let's be thankful for whatever we received in Marvin, quite miraculously and out of the blue 3 years ago, even though it's far from perfect.