I love this app. It revolutionized my library experience simply because I don't have to continually type my library card numbers or PINs now to log into the library website. But everything, from the calendar integration (I use BusyCal) to the menubar star works great.
I would love to have paid money for the app and support its development, because the one thing it isn't is pretty. And I happen to love a beautiful interface. So if the developer would ever like to get some money for this app and add a little bit of eye candy, I'm on board. Right now, with two accounts and nineteen items out from the library, it's just a big fat white eyesore.
But I'm not complaining: in utilitarianism, it takes the cake, and that's what apps are for.