Actively Learn is a digital tool that allows you to easily add notes/questions/resources to digital texts, ones provided for you or ones that you upload yourself. You can easily create a class, add students, add the text and resources; all in a very short time. Students then can use the notes/questions/resources you provide to help them make sense of the reading and improve as readers. There are a lot of free options that you will find useful for your students and some of the premium options even make it worth buying, if you have the funds.
(They even have resources from Project Gutenberg such as The Great Gatsby.)
Watch the video to see the basics of Actively Learn and then start thinking about how you can use it to help your students as they read.