Apple’s App Store for iPhone generates “about four times” the revenue of Google’s Android Market, according to Distimo’s analysis of the top 200 US apps available from the two portals.

Based on its review of the market in the 11 months to November 2011, the company said that “nearly all stores” showed impressive growth in the number of apps available for the period, with all except the already significantly larger App Store for iPhone having at least doubled in size.

While the App Store for iPhone has maintained its lead in revenue terms, the number of downloads made was declining for “nearly the entire year.” The lowest point came ahead of the launch of the iPhone 4S in October 2011, at which point downloads rebounded to the highest point of the period.

Likewise, there was a dip in iPad volumes at the start of the year, which was reversed with the launch of the iPad 2.

App store breakdown
The ranking of the stores in terms of total available apps remained largely the same, with the exception that BlackBerry App World is now slightly larger than Nokia’s Ovi Store.

Distimo noted 400 percent growth for Microsoft’s Windows Phone 7 store, which by the end of November 2011 had more than 35,000 apps available.

There is some difference when it comes to free apps, in that Android Market passed the App Store for iPhone in volume terms during June 2011. Windows Phone Marketplace also passed BlackBerry App World for free apps in May 2011.

The company asserted that the games category is “the most robust,” being the single largest category in most stores, and also generating the most downloads.

The three largest stores for games are Apple’s App Store for iPhone (79,077), Android Market (46,045) and the App Store for iPad (28,683). The ranking order for these three remained the same in 2011.

From its launch late in 2010, Microsoft’s WP Marketplace has overtaken Ovi Store and BlackBerry App World to become the fourth largest platform for mobile games. And in the five months since it launched, Amazon’s Appstore also amassed more games than Ovi Store and App World.

Shifting monetisation methods
Distimo also said that there has been a significant rise in the use of in-app purchases as a monetisation method.

The share of revenue generated by in-app purchases among the top 200 iPhone apps has increased from 29 percent in January to a peak of 53 percent in September, with the number declining slightly to just under 50 percent in October and November.

The trend is even more evident in Google’s Android Market, where 65 percent of revenue from the highest grossing apps comes from in-app purchases. It was noted that there have been well-reported problems for developers generating revenue for paid app sales from Android Market, meaning that “it might be wise to switch to a freemium model if you are a developer for the US market.”

Global perspective
Distimo also noted sharp growth in demand from China, noting that “the US is no longer the single most important country for apps.”

In January 2011, the App Store for iPhone in China generated 18 percent of the total downloads for this country and the US combined. However, by November, this had increased to 30 percent, indicating the pace of growth.

It was also noted that “the US and China are almost equal in size when looking at the number of downloads in the App Store for iPad.” In revenue terms, China still lags, but Distimo noted that the ability for Chinese consumers to pay in their own currency will change this.