I love how this app handles pdf files and I love the style of note taking and highlighting. It could, however, use some improvement when it comes to ePub files. It still gets the job done but I would like to see it handle the ePub files more seamlessly, similar to iBooks. For example, it would be nice if linked references pop up in the main screen rather than jumping to a different page. I realize they show as notes in the margin but it's not quite the same. Maybe it's just me though.