Microsoft introduces a Touch Develop web App Creator for windows 8 and windows phone 8 users.
All know's that there’s a lot of us who come up with great ideas for apps for windows 8 and windows phone 8 but never act on it because of our relative lack of knowledge of programming but now, you can make app for windows 8 and windows phone 8 just by using web browser.
You will have to sign in via your Windows Live, Facebook, or Google account to access the TouchDevelop Web App page. Once that's done, you can begin your great app development career by watching some tutorial videos on how to use the available tools on the site to make Windows Phone 8 or Windows 8 apps.
Source: Microsoft