App analytics firm Distimo said that, at the beginning of February 2012, Microsoft’s Windows Phone Marketplace overtook RIM’s BlackBerry App World in terms of the number of apps available, driven by strong growth in January, when 3,000 new apps were added each week.

The company said that the winner of this two-horse race is not clear yet, with both companies following different strategies to bolster their app numbers.

Microsoft is in the process of rolling out the Windows Phone store to more countries in order to gain market power. RIM, meanwhile, is looking to lure Android developers to the BlackBerry fold, including offering free PlayBooks to those submitting products.

According to Distimo, RIM’s strategy appears to be bearing some fruit, with more new apps added to App World than Windows Phone Marketplace in the first week of February.