Document Viewer is a free app that lets you read all types of documents, including PDFs, Excel, Word, Txt, Slide, Djvu, Mobi, Epub, and more. With this app, you can access all your documents in one place. You can even mark your favorite documents and search for files with ease. The app also includes an ebook reader, allowing you to read Djvu, Epub, Mobi, Fb2, and other ebook formats.

One of the app's unique features is the ability to take a screenshot and write notes on the photo. You can also share files via Facebook, Twitter, email, and other platforms. Additionally, Document Viewer allows you to sort files by access date, created date, and alphabetical order. Overall, Document Viewer is an excellent app for anyone who needs a simple and convenient way to read their documents and ebooks.