Google today released an update to the Google Books App.
The update now brings additional functionality including giving you the ability to upload EPUB or PDF files to your library from your phone or tablet.
The full changelog is as follows
Books open more quickly and smoothly.Upload EPUB or PDF files to your library from your phone or tablet. From email or Downloads, touch the file to open it and choose Upload to Play Books.Improved look and feel of highlights and notes.Lower brightness settings, for better reading in low light.Read any book in landscape view.Dismiss recommended books in Read Now.Additional improvements in performance, stability and accessibility.