Google Play Books lets you search, preview, and buy millions of books using Google Book Search. Books in the public domain and certain copyrighted books can be read and downloaded in their entirety for free. You can buy ebooks for reading on your computer, Apple device, Android device, Nook, or Sony eReader in the Google ebookstore. All purchased eBooks are backed up online, and your page positions are automatically synced between devices.
- You cannot buy books to put onto a regular ereader from this, it is for Android tablets/phones only.
- Allows epub-format books to be uploaded, at which point they become available on all devices you have GPB installed on. I use this for all my public-domain (Gutenberg, Azora-bunko, etc) ebook reading.
- calibre is a ebook converter, not a store or reader