I personally use the Goodreads App. It's great but so far I haven't been able to figure out how to find friends and befriend them. Know what I mean?
And I really really wish they'd update the app so that you can give .5 stars to books as well. A lot of people wish this and I am certainly one of them. Because you can't rate a book four point five, it kinda brings down the average rating of a book. Which, frankly, sucks.
I absolutely LOVE the idea of scanning books, because it saves so much more time than having to type it.
I love the idea of Reading Challenge, it's such a great way to read more books. Although I really wish they'd have settings to select from which month to which month instead of the entire year. Because I started Goodreads in the middle of this year, so I don't remember all the books I read previously. That means my Read Books diminishes.
I gotta get going but, just so you know, Goodreads is great! And if you haven't already checked it out, you really should.