How I Use It
Subtext is an excellent app for encouraging close reading by students. You can set up your class, pull in a text(free or one from Google books) and insert your own comments and questions or let students highlight and make their own comments and questions.
Subtext is an excellent teaching tool in a 1:1 device environment, because of how it allows students to collaborate with each other through annotating and discussing a piece of literature or text or historical document. I wish it didn't require book by book purchase for more current titles. But it is free and you can pull in free titles that are out of copyright--anything from Declaration of Independence to Shakespeare for close reading.