According to Piper Jaffray’s Gene Munster, Apple device owners are still hungry for mobile applications, so much that they are buying 61% more apps than they did in 2010, Fortune reports.

Monitoring the health of the App Store can be troublesome, especially because Apple only tends to release information when it paints the company in a good light. Despite the announcement the App Store had passed 15 billion downloads, Munster was forced to find his own way of disclosing how well the marketplace was performing, creating a spreadsheet to compare and contrast previous App Store metrics.

The report shows more users are buying apps, investing in more expensive apps despite the fact 82% of apps on the App Store are free:

The average iOS device owner will download 83 apps in 2011 vs. 51 in 2010, a 61% increase year over year. “Smartphone users are showing an increasing appetite to use apps to add features to their phones,” Munster writes, “and iOS has the leading app ecosystem.

The ASP (average selling price) per app is rebounding. ASPs are up 14% y/y in 20111 vs. an 18% decline in 2010. “After the initial race to the bottom in App Store pricing,” says Munster, “we are seeing users pay up to add features and games to their iOS devices.

Apple’s App Store has more than 425,000 apps. The Android Market has 200,000. In May, Google announced its 4.5 billionth app download, compared with Apple’s 15 billion as of July 7.

82% of the apps in Apple’s store are free. The 18% that users have to pay for have an ASP of $1.44. According to Munster, the increase in ASP is driven by the more-expensive iPad apps that represent a growing percentage of app downloads.

As the App Store has evolved, developers have learnt what sells and what doesn’t, tuning their pricing strategies and launches to better suit the needs of their customers. Many iOS device owners will download the free version of applications before they pay for the premium version, perhaps explaining why there is such a high number of free apps.

The demand for feature-rich apps is increasing and consumers are ready to spend money to get them. Is there a better call to action for an aspiring iOS developer?