Android overtook iOS as the market share leader in mobile application downloads for the second quarter of 2011.

Android’s share of mobile app downloads was 44 percent during the second quarter while iOS had a market share of 31 percent, according to new research from ABI Research. Contributing factors to Android’s strength in the second quarter include its open source strategy and slowing demand for iPhones during this period.

Global app downloads for 2011 are expected to total 29 billion compared with 9 billion in 2010, according to ABI Research. The growth is attributed to the proliferation of smartphones, with the smartphone install base expected to grow 46 percent this year.

Slower iPhone sales
The fact that Android is a free platform has expanded the Android device install base.

Android’s install base now exceeds iOS by a factor of 2.4-to-1 worldwide, according to ABI.

The strong install base has, in turn, driven growth in the number of third-party multi-platform and mobile operator app stores.

These factors helped drive the number of app downloads in the second quarter.

App downloads for Android also got a boost from the fact that iPhone shipment growth slowed in the second quarter as consumer anticipation over the delivery of a new iPhone tamped down sales.

iPhone shipment growth in the second quarter slowed to 9 percent from 15 percent in the prior quarter, according to ABI.

Both Apple and AT&T reported that iPhone sales slowed down recently as consumers waited for the launch of the new iPhone before they bought or upgraded.

During the same period, Android smartphone shipments increased 36 percent compared with 20 percent in the first quarter.

However, despite leading in total mobile application downloads, Android’s app downloads per user lag behind Apple’s by 2-to-1.

This is because Apple’s superior monetization policies have attracted good developers that have created a better catalog of apps and a better customer experience.

The information is part of ABI Research’s latest “Mobile Applications Market Data” report, which tracks mobile application downloads and revenues.

Final Take
Chantal Tode is associate editor on Mobile Commerce Daily, New York