• by Mark Walsh  @markfwal, September 6, 2013

New comScore research underscores how Google and Facebook are dominating content use on smartphones, especially when it comes to apps.

Google ranked as the No. 1 property in July across the mobile Web and apps, reaching an average 92.6% share of the mobile media audience for the three months ending in July. Rounding out the top five publishers were Facebook, with 86.3%, Yahoo (81.7%), Amazon (66.8%) and Apple (50.2%).

Looking just at app use, Facebook led the way with 76.1% audience share, trailed in the rankings by no less than five separate Google apps: YouTube, Google Play, Search, Maps, and Gmail. Each claimed between 45% and 53.7% share. Others in the top 15 included Apple (43.9%), Pandora (40.4%) Yahoo Stocks (31.2%), Instagram (26.4%), and Twitter (21.3%).

Facebook over the last year has moved aggressively to turn its increasing mobile usage into more ad dollars. An eMarketer report last month estimated the social network’s share of global mobile ad revenue will jump to 15.8% this year from just 5.3% in 2012. Google is still expected to be the biggest mobile player, with 53.2% share.

The latest comScore data also showed that iOS continued to chip away at Android’s lead in the smartphone market. The Apple platform ran on 40.4% of U.S. smartphones through July, up from 39.2% in April. Android was essentially flat at 51.8%. BlackBerry continued to lose ground, dipping to 4.3% in July from 5.1% three months ago, while Windows Phone was flat at 3%. Symbian is down to just 0.3% share.

With four out of 10 U.S. smartphones being iPhones, Apple again dominated among handset manufacturers. But No. 2 Samsung drew a bit closer in July, increasing its share to 24.1% from 22%. A distant third was HTC, which saw its share slip nearly a full percentage point to 8%; Motorola, falling to 6.9% from 8.3%; and LG, roughly flat at 6.8%

With the expected launch of the next-generation iPhone on Tuesday, Apple has the opportunity to take back share from Samsung while further narrowing the gap with Android in the U.S. Separate data from mobile ad network Millennial Media on Friday showed that iOS accounted for 42% of impressions in the second quarter, up from 34% a year ago. Android’s share increased to 51% from 46% a year ago.