New today is Cover, a client for CBR/CBZ/CB7/PDF/EPUB format comic books, mapped to the folders and files on your device, plus your OneDrive, and with a slick interface. Although Cover doesn't include a demo book out of the box, it's easy to grab (DRM-free) comics for yourself at imagecomics.com or comicbookplus.com (among other outlets). If you're a comic book fan then you've probably got your own digital archive already.

From the Store description:

Features:

• Comic book management with shelves (folders), read/unread, page count, current page,...
• Add folders to the library or open standalone files
• Supported file types: CBZ/ZIP, CBR/RAR, 7Z/CB7, PDF (beta), EPUB (images only)
• Supported image types: JPEG, PNG, GIF, BMP
• In-app purchase to unlock unlimited library
• Open files directly from Files app
• Indexed library for quick search
• Customizable page layout : single or dual page
• Pinch zoom, swipe et tap supported in reading screen
• left-to-right or right-to-left reading (aka Manga mode)
• 3 differents fitting mode (width, height and page)
• Ability to pin a comic on the Start screen
• Automatic detection of page borders (to remove them)
• White or black reading background
• Transparent live tile

Here's Cover in action:

You can grab Cover here in the Windows Phone Store. (There are other comic readers in the Store, notably Comic Time, but Cover seems a cut above the rest.)

Like the (universal) Windows version, Cover for Windows Phone is free to download with a limit of 25 comic books at once. For 1,49€ you can unlock the library up to 250 books, and for 2,99€ you can unlock the unlimited library. And, being an universal app, if you unlocked Cover on Windows, it will also be unlocked on Windows Phone, and vice-versa.