UPDATE
I just wanted to chime in with everyone else complaining how Marvin hasnt synced with Calibre since iOS 8.3 and if your try to download multiple files from DropBox, Marvin crashes. The bottom line is Marvin hasnt been updated in quite some time, and it doesnt appear the developer has any plans to do so. Im downgrading my original 3-Star review to 2.
ORIGINAL REVIEW
Marvin quickly became my go-to ePUB reader primarily due to its [more] robust support of metadata and per-book preferences. In all other aspects of reading a book, it’s as capable as iBook so long as the lack of curled-page flip animations aren’t a deal-breaker.
That Marvin lives outside the Apple ecosystem is both a plus and a minus, and you’ll have to decide for yourself the net. For me, the flexibility of syncing through myriad methods (dropbox, a 3rd party plugin + Calibre, OPDS and the web) is a boon. Others will no doubt find this added layer of complexity annoying.
Marvin is also comparatively feature-rich, and the way to some its features is not always intuitive. Marvin’s online help is extensive, however, and one really ought to read it through before using Marvin. Of course, that’s pretty un-Apple. Take, for example, dictionary lookups. When I first started using Marvin, I was shocked to discover I couldn’t highlight and look up the definition of a word. Turns out, you can, but this feature (and a whole lot of other things) is turned off by default. You have to enable such context-menu items in the preferences on Marvin’s home screen. So, on the one hand, runes out Marvin has a whole lot of things I can customize and turn on and whatnot, on the other hand it kinda felt like I was in a Windows App.
It’s apps like Marvin that make me wish for half-star increments, because I really want to give it 4.5 stars. In every metric that I care about, Marvin outperforms iBook and ultimately I’m okay with the added complexities Marvin’s power introduces. I basically love everything about it with the exception of no pdf support. Unfortunately, for me, the lack of pdf support is a pretty big deal, and it’s now the only reason I ever launch iBook. In Marvin’s online FAQ, the author claims such support might happen, but that he’d rather do one thing well rather than spread himself too thin. I get that. For me, however, I would far rather pay $5 for a pdf plugin than $1 for a color theme.