For newcomers to the app, the PhoneGap Developer app aims to lower the barrier of entry to creating PhoneGap apps. You can immediately preview your app on a device without installing platform SDKs, registering devices, or even compiling code. Plus, you have full access to the official PhoneGap APIs.
You can learn how to install and use the app on our original blog post. Since the Android, iOS, and Windows Phone apps use the same codebase, the usage is identical. However, a fun fact is that you can now develop on an OS X machine and preview on a Windows Phone device. Cross-platform, indeed!
Thanks to everyone for your feedback and help so far! We held a public Windows Phone beta and received a lot of great ideas on the issue tracker. Please continue helping us improve the app by reporting issues, requesting features, and contributing to the open source project!