One of Microsoft’s problems in attracting people to write Windows Phone 7 applications is that the user base is much smaller than those of the iPhone or Android, so app developers tend to focus on those platforms. Now, Microsoft is tryin

g to make it easier for people to take the apps they’ve developed for the iPhone and make them work on Windows Phone.

With the iPhone/iOS to Windows Phone 7 API (application programming interface) mapping tool, released on Friday, developers have a new online resource for doing this conversion.

Essentially, the API mapping tool works like a foreign-language dictionary, said Jean-Christophe Cimetiere, Microsoft senior technical evangelist for interoperability. Developers can go through the code of their iPhone app and find the equivalent API calls for a Windows Phone 7 app.

“For this first round we focused on identifying the one-to-one mapping when it exists,” Cimetiere wrote in a blog post. “In the following versions we’ll expand the scope and anytime the concepts are similar enough, we’ll do our best to provide the appropriate guidance.

“Of course, this is a work in progress, coverage will expand and more iOS APIs will be mapped soon.”

More information on the tool is available on the Windows Phone Developer Blog.