A free program for Android, by Randierinc.

The All Document Reader is a document viewer app that allows you to view Word, Excel, PowerPoint, Text, and PDF files on your mobile phone. It is a simple and easy-to-use application. You can view documents on your phone and also print them.

This app is a powerful and easy-to-use PDF viewer app that allows you to view all kinds of PDF files on your phone. With it, you can open all kinds of files like docx, ppt, excel, and xls. It also allows you to view lectures and notes in any format. 

This application will just work for you like a portable pocket document reader. You can take your lectures in any format of documents and read them easily on your phone.