• by Mark Walsh , December 13, 2011

It’s clear that Apple’s iOS mobile platform has not lost any appeal for app developers, despite the explosive growth of Google’s Android operating system this year.

New data from app advertising and analytics firm Flurry shows that iOS actually expanded its share of new project starts among developers to 75% in the third quarter, from 63% at the start of the year.

Conversely, Android’s share has slipped to 25% from 37% during that period, and Flurry projects that iOS will claim 73% share to Android’s 27% in the fourth quarter. At first glance, the findings seem counterintuitive, considering that Android has surged ahead of its Apple counterpart on smartphones in the U.S. and worldwide.

Data released Tuesday by NPD Group, for example, indicates that Android commands more than half (53%) of the smartphone market, compared to 29% for iOS. In November, Google said it had released 200 million total Android devices and was activating 550,000 daily.

The previous month, Apple said it had an installed base of 250 million iOS devices, with 450,000 activated each day. At that rate, Android is poised to eventually overtake its main rival. But when it comes to apps, iOS still has the upper hand. That is partly because of the iPad’s dominance in the tablet market, making it by far the No. 1 option for developers creating apps in that category.

Apple’s move to extend iPhone distribution beyond AT&T to Verizon Wireless in February and Sprint in October also helped enhance the standing of iOS with developers. The launch of popular devices -- namely the iPad 2 earlier this year, and the iPhone 4S in October -- gave iOS another boost. The arrival of the latest iPhone model, in particular, has prompted developers to ramp up activity in support of the phone leading up to the holidays.

Anecdotally, Flurry points out that developers say they make about three to four times as much on iOS as Android. Looking at in-app purchase data among top apps, the company found that for every $1 generated on iOS, the same app will produce 24 cents on Android.

The difference comes down to a smoother customer experience on iTunes than via the Android Market, especially in regard to payment. Upon setting up an iOS device, a user must associate either a credit or gift card with their iTunes account. That has not been the case for Android. By rolling Google Checkout into its mobile Wallet offering last month and kicking off a 10 cent-app sale in December, Flurry notes that Google is trying to improve revenue potential for developers in Android Market.

Still, Google recently announced hitting its 10 billionth download, and is now generating 1 billion downloads a month. And Google chairman Eric Schmidt boasted at the Le Web conference in Paris last week that in six months, Android would supplant iOS as the platform that developers target first. But based on current trends, that seems unlikely.

Flurry says more than 55,000 developers use its analytics software across 135,000 apps. For its latest study, the company looked at new project starts in 2011 encompassing about 50,000 apps.