It’s really a shame that Microsoft doesn’t document the widget API any better than it currently does. It actually has quite a bit of potential as a platform, but I’m sure developers find it problematic that the documentation is sparse, and debugging facilities are practically nonexistent.
There is a short document on MSDN, here for those who want to get started. One small problem though. Microsoft Windows® Mobile Marketplace, the place where these widgets are supposed to be distributed will charge a hefty price for developers to publish on it. I guess I didn’t really read the terms that carefully before and assumed that Microsoft would have put their terms to be competitive with the iPhone SDK. It turns out that Microsoft is charging a 99$ application fee and 99$ per application, which in my opinion is a total deal breaker. If Microsoft wants WM to survive as a platform, they probably should make marketplace – a place where free apps can be distributed as well as pay apps – and I doubt too many developers will be willing to shell out that fee. I was for a time considering distributing apps on Marketplace, but sorry Microsoft, you’ve lost my vote on Marketplace … I’m not even going to bother anymore. Sure, they’re running a “limited time promotion” – five free apps with your $99 application fee, but come on Microsoft, as big of a software giant you are, your infrastructure for software distribution is currently worse than Apple’s, which means you should be offering better terms than Apple - Apple charges only a $99 application fee, and no per application fee. Honestly, which developer is going to put their free apps on Marketplace for 99$ out of their own pocket? If Microsoft were to do this right, they would have offered a $50 application fee and no per application fee to attract developers. It’s almost like Microsoft just wants Windows Mobile to die… I’m not even going to get started on how Windows® Mobile Marketplace is not available on versions of Windows Mobile prior to 6.5.
About the WidgetAPI, you can find the values in:
[HKLM\Software\Microsoft\Shell\Widgets\Settings\”number of your widget”]
Where you’ll find the key/value pairs of your applications in plaintext. Guess there’s not much you can do about saving passwords in widgets, except warning the user that they will be stored in plaintext.