Recommended for English lessons: Google Books

Students who are reluctant readers will begin reading, once they grow awareness of this book recommendation service by Google Inc. People can search and browse, even purchase from Shakespeare to Marvel comics, it is for any age, from primary to adults. The purchasing is from the most common booksellers e.g. Barnes & Noble, Amazon or Waterstones. For e-book and technology obsessives, there is an Android app and e-books to download for your Kindles, Kobos and Nooks. It even allows you to read books for free, so no online freenium.
Overall I think this will be a great resource to encourage reading among adults and children.

Site-http://books.google.com

Android app: https://play.google.com/store/apps/details?id=com.google.android.apps.books&hl=en_GB