Despite the Android operating system's rapid growth, one Google manager says the company isn't happy, as it wants more people to buy paid apps.

Eric Chu, Android's platform manager, told a group of developers at an event in San Francisco that not enough people were purchasing apps for the Android phone. He said Google is simply not happy with the number of app purchases versus the number downloaded for free, especially compared to the iPhone, according to a report from Forbes.

Chu outlined a plan for Google to fix the Android app sales in 2011. This included unveiling an in-app payments system that will allow people to purchase virtual goods, allowing people to charge apps to their phone bill, better ways to discover new apps, including more social-netowrk based methods and allowing developers to use HTML5 to create apps.

Despite the grumbling from Google about Android apps' financial return (or lack thereof), the operating system is on the rise as is all app-related revenue, according to two recent reports. One from research firm IDC says developer interest has nearly closed the gap on the iPhone.

Meanwhile, the market for all mobile applications has and will continue to grow, according to a report from Gartner. The report said the global mobile application store revenue is projected to surpass $15.1 billion in 2011, a 190 percent increase in revenue from 2010.

Many are wondering if the app frenzy we have been witnessing is just a fashion, and, like many others, it shall pass. We do not think so, said Stephanie Baghdassarian, research director at Gartner, in a statement.

However, Gartner's report did validate some of the frustration of Google's managers. It said in 2010, the Apple's App Store had close to nine out of 10 app downloads. It said it will remain the single best-selling store across the forecast period, which is through 2014.

Setting up a successful application store is far from simple. Application store owners need to rise to the challenges of attracting developers, organizing content and engaging users throughout the life of the store in order to remain profitable, Baghdassarian said.