Prior to your submitting an app to Marketplace (and telling all your friends and family to download it!), you will need to register as a developer and create an account. As Marketplace is currently open for early access app submissions and by invitation only to registered developers, you’ll not want to wait to register. If you have an app ready to be uploaded, be sure to understand the application requirements and policies for apps and games submission, which you can download here:
[go.microsoft.com]