The app store analytics firm Distimo has released its latest report on the size of the various mobile app stores, as well as the types and prices of apps that are most successful there. The report compares the Apple App Store for iPad, Apple App Store for iPhone, Apple Mac App Store, BlackBerry App World, GetJar, Google Android Market, Nokia Ovi Store, Palm App Catalog, and Windows Phone 7 Marketplace. Despite all the buzz surrounding apps and mobile devices, the report finds that these stores only experienced moderate growth over the last few months.

No surprise, the Apple App Store still dominates, fueled primarily by the number of apps available for iPhone. However, when you separate that store into two – iPhone apps and iPad apps – you get a different picture. Despite being the largest store, the Apple App Store for iPhone was among the slowest growing stores in terms of relative growth. Even so, that growth was still second only to the Google Android Market in terms of absolutely growth.

The Google Android Market is now the clear leader in terms of free apps. As of March 2011, the total number of free apps there exceeded that in the Apple App Store for iPhone by more than 10,000. However, the number of paid apps in the Android Market is barely a third of the number of paid apps in the Apple App Store.

Distimo predicts however, that the Android Market will catch up with Apple iPhone’s App Store by July. It also predicts that the Windows Phone 7 Marketplace will be larger than the Nokia Ovi Store and BlackBerry App World, prior to the Windows Phone 7 Marketplace being available for even a full year.

The report also assesses how the introduction of more tablets may change the make-up of these app stores. Will other tablets follow the same pattern as the iPad did in terms of app sales? According to Distimo, iPads apps have become more expensive over time, while other stores seem to follow the opposite trend.

Regardless of the platform, the report does point out that many of the top app developers publish across platforms. 58% of the 50 most popular publishers have already developed applications for non-Apple platforms.