Distimo, a Netherland based company gives in-depth App Store related reports and analytics and some of them are provided for free. This is really helpful if you are tracking different App Store trends. Distimo is built to solve the challenges created by different App Store marketplaces with isolated app store details. Now, every mobile developers/brands have their own market place making it very hard for technologists to understand the mobile app trends. 
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Distimo Reports provides in-depth, analytical reports for companies interested in the mobile application ecosystem, giving valuable insight into important trends happening within application stores.
Monthly Reports
Distimo publishes free reports every month, highlighting trends in the different mobile application stores. Archived reports can be downloaded from archive section.
Following Market places are covered.
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Apple App Store
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BlackBerry App World
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Google Android Market
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Nokia Ovi Store
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Palm App Catalog
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Windows Marketplace
Custom Reports
Distimo can also give customized report for specific mobile application store analytics that are relevant to your company.
Apart from Distimo Report, there is also free App Store Monitor tool available for you! Distimo Monitor collects all relevant statistics of your applications, automatically and every day. View daily downloads and revenue figures of all your applications and analyze their ranks, worldwide.
