A year on from when the Windows Phone 7 developer tools were first made available to the app building community, the Windows Phone Developers Blog has posted some interesting app stats:

There has been 1.5 million downloads of the WP7 developer tools (Visual Studio Express for Windows Phone and Expression Blend 4 for Windows Phone) - "the number of downloads equates to the size of the entire population of Philadelphia".

36,000 people from the AppHub community have paid up to become members of the Windows Phone developer community.

And there are 11,500 apps now available for users. That's 11,500 proper apps, not lite apps or personalisation options. The team were keen to put the boot in on its rivals when it came to app counting as well.

"We recognise the importance of getting great apps on our platform and not artificially inflating the number of actual apps available to customer by listing 'wallpapers' as a category, or perhaps allowing competitor’s apps to run on the platform to increase tonnage," reads the blog.

"Finally, we don’t double and triple count apps which are submitted in multiple languages."

Of the 11,500 apps, 7,500 are paid apps and there are 1,100 apps that are generating developer revenue using the Microsoft Advertising Ad Control. Each WP7 users has downloaded an average of 12 apps.

It's also interesting to note that 60 per cent of the registered developers have yet to submit this app. A statistic that is sure to lead to an explosion in the figures above down the line.

Have you tried WP7 yet? If so, what do you think? The big comeback Microsoft had hoped for, or another poor mobile OS? Let us know using the comments below.