Those with early access to Windows 10 updates (Windows Insiders in the US) can now buy ebooks for their PC or smartphone from the Windows Store but they won’t need a Kindle-style app to read because this functionality is built into the Edge web browser where all downloaded ebooks will open automatically. As you purchase ebooks your library will appear right next to favourites, history, downloads and reading list within the Edge browser.
The official Windows Insider blog says that Edge will support an ebook reader-style layout, offline reading, Cortana-assisted search and the ability to customised font, text size, theme and layout.
The Edge browser will also be compatible with the EPUB file format as well as PDFs, obviously, and books purchased in Windows Store but there is no mention of the file format these books will take. It is likely, however, that MOBI (Kindle’s ebook file format) is unsupported.