During the 3-month average ending in July 2012, 37.9% of US mobile subscribers accessed a social networking site or blog on their device, up about 5% from 36% during the 3-month average ending April 2012, and up almost 26% year-over-year from 30.1% in July 2011, according to comScore Mobilens data. Supporting this finding is an August report from Distimo, which reveals that the download volume among the top 100 most popular social applications in the Apple App Store for iPhone in the US grew 193% between July 2010 and July 2012. That 193% growth rate is far higher than the 43% increase in downloads for the top 100 most popular free apps overall in the Apple App Store. Within the US, the 100 most popular social apps account for 20% of the top 100 most popular apps in general, by download volume. This is the highest percentage of the 21 markets studied, with the overall average at 13%. Read the rest at MarketingCharts.