In the movie "Jerry Maguire," Tom Cruise uttered the infamous phrase "Show me the money." But in the mobile world, the comparable phrase is closer to "Show me the apps." And when it comes to Windows Phone, the apps picture is fantastic. In fact, as I noted in Here Comes Windows Phone 7.5, there are over 30,000 apps available for Windows Phone already, including about 90 percent of the "must-have" apps cited by iPhone and Android users.

The reason Microsoft is so successful at this game is that the people in charge of Windows Phone developer evangelism at the software giant just get it. They court developers aggressively, they make great efforts to attract developers that already have experience on other mobile platforms, and they write great tools and documentation.

This week, Microsoft updated its guidance and porting tool, which are aimed at helping iPhone and Android developers port from those platforms to Windows Phone. And in a related move, Nokia discussed how the Windows Phone porting tool has been updated to include migrating from Nokia Symbian Qt.

"Today I'm excited to announce new guidance based on migration samples and a SQLite to SQL Server Compact database conversion tool," JC Cimetiere wrote on the Windows Phone Developer Blog. "We hope that these new items combined with our previous extensive guides (for Android, iPhone, and Symbian Qt) will accelerate your ramp up time and improve your experience in porting apps to Windows Phone from iPhone and Android."

The Microsoft documentation discusses migrating apps with in-app advertisements,

geo-location, and group messaging from iOS/iPhone or Android to Windows Phone. Each example includes sample code, porting notes, and other documentation. And with this new version, there's also a SQLite2SQLCE tool that will convert SQLite databases into the Microsoft SQL Server Compact (SQLCE) format supported on Windows Phone 7.5.

Here are the links to the guides:

Windows Phone 7 Guide for Android Application Developers

Windows Phone 7 Guide for iPhone Application Developers

Windows Phone 7 Guide for Symbian Qt Application Developers

Meanwhile, on the Nokia Conversations blog, that company talks up the Symbian Qt porting guide.

"The mapping tool is a utility for developers that serves as a translation dictionary between the Windows Phone platform and other mobile operating systems," the post reads. "The tool enables developers who are familiar with APIs from other platforms to see the equivalent class, method or notification events inside Windows Phone. Intended strictly for developers, the Windows Phone API mapping tool includes core libraries for Qt 4.7 for Symbian, which includes: QtCore; QtGUI; QtLocation; QtNetwork; QtSql; QtXml; QtWebKit; QML Elements; and QML Components. There are also code samples and tutorials to help developers too."

Good stuff. Hooray for developers.