Microsoft keeps tweaking its web-based Windows Phone App Studio development tool, though it hasn't yet shed the 'beta' tag. The latest updates include support for using NFC to share your app and the ability to access other phone features such as making a call or listening to music from within your app.
There are also tweaks to how RSS feeds are accessed offline. Hit the blog post to learn more.
Developer feedback leads to new features in Windows Phone App Studio Beta [Windows Phone Developer Blog]