With a gaining 5.2 percentage point to capture 36.4 percent of all smartphone users, Google's Android was at the top in the U.S. smartphone operating system market for the three months ending in April, a ComScore report revealed.

It was Apple's iOS that came in second with a 1.3 percent gain grabbing 26 percent share of the smartphone market, according to the report.

Losing almost five points from the previous quarter, RIM's BlackBerry came on third on the list with a 25.7 percent market share. Microsoft's Windows Phone and HP's PalmOS are also among share losers, who were in the fourth and fifth place, respectively. With a 6.7 percent market share Microsoft lost 1.3 points from the previous quarter, while HP's PlamOS managed to capture only 2.6 percent of the entire U.S. smartphone operating system market losing 0.6 point from the last quarter, said the ComScore report.

On the other hand, Samsung was at the top spot among the mobile phone makers with 24.5 percent of the U.S. market. Samsung was followed by LG with almost 21 percent and Motorola with 15.6 percent, the report said. Apple overtook RIM to settle at fourth with 8.3 percent of the market. According to the report, 234 million people in the U.S. owned mobile phones during the three-month period.

The report further said that text messaging was the hottest activity for almost 69 percent of mobile phone users. While browsing the Web on phone was popular among 39 percent, 37.8 percent of the users did apps downloading. Apart from all these, other common activities among mobile phone users were accessing social-networking sites and blogs, playing games, and listening to music, said the report.