Android has once again solidified its place as the top of the charts in terms of being the most popular mobile ad network.

According to Millennial Media, Android has taken 51 percent of all ad impressions on the network for the second quarter in 2013. The number was up 46 percent from what people had seen last time around in the second quarter of 2012 and down just one point from this year's first quarter.

Nipping closer than anyone else at Android's heels was, of course, Apple's iOS. However, Apple Inc. showed a healthy gain in ad impressions according to CNET. The company rose to 42 percent, up from 34 percent from this same period last year. Together, the two operating systems account for 93 percent of all impressions, leaving little room for competition from other mobile platforms. BlackBerry took third, Windows fourth and Symbian in last.

BlackBerry saw its OS share fall to seven percent from 15 percent last year. Meanwhile, Windows Phones and Nokia's Symbian, which scored 4 and 1 percent respectively, in 2012's second quarter didn't even register last quarter.

Among device makers, Apple reigns supreme with 39 percent of all ad impressions. The iPhone was the top dog with 22 percent of the share. Meanwhile the iPad and iPod Touch took third and fourth places respectively among the top 20 devices listed.

Samsung followed in a close second with 26 percent share thanks to its Galaxy S smartphone family. The Galaxy S smartphone took number 2 as the device makers with the highest ad share in the top 20 with 9.8 percent share. The Galaxy Note proved to be an extremely helpful device for the company with 44 percent of its ad impression gain.

The chart with the information on it can be seen above courtesy of Millennial Media via CNET.