The Windows 8 app store may have over 30,000 apps, but the pickings for comics fans are pretty slim. At the moment, there appears to be only one dedicated comics app in the store, although there are several ways to read comics using other apps.
One app is the behemoth of the digital comics world, Comics by comiXology, which carries over 30,000 titles from every major comics publisher except Dark Horse. It has new releases every Wednesday, the same day the comics come out in print; unfortunately, most are priced the same as print copies. However, there is a substantial back catalogue that is priced at 99 cents or $1.99, as well as a good selection of free comics. ComiXology also has a web store and apps for pretty much every device imaginable, and you only need a single account for all of them, so the comic you buy on one device will be available on all the others.
Because it is so well designed and comprehensive, comiXology may be the only app that comics fans need, except it doesn’t carry much manga, and (as noted above) it doesn’t carry Dark Horse comics. Dark Horse does sell comics via its web store, which should work on any mobile browser.
Amazon has a Kindle app for Windows 8, but not all graphic novels are supported, so check carefully before you buy. A random check of DC and Marvel graphic novels showed that they were available for the Kindle Fire and the Kindle apps for iPad and Android, but not for Windows 8.
You’ll have better luck with the Nook app: The DC and Marvel graphic novels available in the Nook Store can be read with the Nook app for Windows 8 tablets. In addition, the Nook store carries Viz manga and Classics Illustrated comics, both of which will work with the Nook app for Windows 8.
There is another alternative, but it won’t work for most mass-market comics: You can use the Windows Reader to read comics in PDF form. The problem with this is that Marvel, DC, and most other publishers won’t sell you comics in PDF form. You can buy comics from smaller indie publishers through Drive Thru Comics or Eyemelt. For manga fans, Digital Manga, GEN Manga, and Viz’s Sublime yaoi manga imprint offers many titles as PDFs, as well. You can also download free Golden Age comics that are in the public domain via sites like The Digital Comic Museum, Comic Book Plus, and the invaluable Archive.org. And finally, this is a little roundabout, but you can buy comics on DVD via Amazon and read them in a PDF reader as well.
It looks like there are a couple of Windows 8 apps, including Comic Book Reader and POW! Comics Reader, that can handle PDFs and comics in the CBR and CBZ formats, which are used by some sites. A good PDF reader should be able to cover almost everything they can, however.