MetroIf you want to use the-frontend-style-that-everyone's-just-going-to-keep-calling-Metro, then your choice is easy -- you'll have to get your app certified by Microsoft and distribute it through the Windows Store. This is the only way to run your app on a Windows RT machine like the Surface. Metro is the painstakingly designed, carefully curated front-page of the new Windows experience, and Microsoft is betting that you'd rather see your app on the front-page than the dusty old service tunnels of the desktop environment. If you want to build a Metro app, you'll need Visual Studio 2012, which brings us to...
CostsThe full version of Visual Studio 2012 will run you about $500. There's a one-time fee of $49 for a private developer to get apps into the Windows Store ($99 for corporations), and then Microsoft takes a 30 percent share of your app's haul, the same as Apple's cut in its app store. If your app achieves $25,000 in revenue, Microsoft's share falls to 20 percent for the lifetime of the application.
For many developers, these costs will be worth the visibility. If you're releasing a core utility like an RSS reader, text editor, or task manager, you're going to see a hell of a lot less competition -- and more exposure -- on the Windows Store than Google Play or Apple's app store, at least for now. But if you're, say, an established game developer like Minecraft's Markus Persson, with an existing userbase and strong revenue stream, you might not be so eager to share with Redmond.
One important distinction between the Windows Store and the Apple App Store: Microsoft allows vendors to use their own payment platform for in-app purchases.
Content RestrictionsMicrosoft caused a stir when it announced that games rated above PEGI 16 (a European content rating) or ESRB M wouldn't be allowed in the Windows Store -- meaning popular games like Skyrim could theoretically be blocked. This morning, Microsoft's corporate vice president of web services Antoine Leblond announced that the company would "relax" this restriction starting in December, reassuring both consumers and developers that mainstream games wouldn't be banned from the store. Still, Windows Store apps must meet the requirements outlined here. Some of those requirements deal with security, privacy, and user experience, but the content restriction section reads:
We understand that in some cases, apps provide a gateway to retail content, user generated content, or web based content. We classify those apps as either Storefront apps, whose primary function is to aggregate and sell third party media or apps, or Streaming apps, whose primary function is to aggregate and stream web-based images, music, video or other media content. In some cases, it may be acceptable for a Storefront or Streaming app to include some content that might otherwise be prohibited in a single purpose app.
- Your app must not contain content that advocates discrimination, hatred, or violence based on membership in a particular racial, ethnic, national, linguistic, religious, or other social group, or based on a person’s gender, age, or sexual orientation
- Your app must not contain content or functionality that encourages, facilitates or glamorizes illegal activity
- Your app must not contain or display content that a reasonable person would consider to be obscene
- Your app must not contain content that is defamatory, libelous or slanderous, or threatening
- Your app must not contain content that encourages, facilitates or glamorizes excessive or irresponsible use of alcohol or tobacco products, drugs or weapons
- Your app must not contain content that encourages, facilitates or glamorizes extreme or gratuitous violence, human rights violations, or the creation or use of weapons against a person or animal in the real world
- Your app must not contain excessive or gratuitous profanity
These are pretty much in line with Apple's content restrictions, but may come as a surprise to some Windows devs unaccustomed to dealing with content standards. If you're working on, say, a particularly adult-oriented indie game, you may want to keep a close eye on the progression of the Windows Store's stance on adult content.
App stores offer a lot of benefits for both users and companies. For devs, they generally require a trade-off: absolute flexibility for visibility and ease of user experience. Whether this trade-off makes sense for your app depends on exactly what you want to do with it. If you're developing for Windows 8 right now, we'd love to hear whether you're targeting the Windows Store, and why.