Free at Kobo US: http://store.kobobooks.com/en-us/ebook/war-and-peace-81
Free at Google Play: https://play.google.com/store/books/...d=Ch43AwAAQBAJ
As a reminder,
Paradise Lost is available in a similar format (bonus material for a modern book included along with the entirety of the text), going on two years now:
http://www.amazon.com/Paradise-Lost-.../dp/B009G3T4Y0
The reviews are erroneous on Amazon, they mixed all the listings' reviews.
The formatting is decent.