Many have underestimated Android’s fast growth in the past, and some still do even now. But Android is going to put another “win” on its belt this year when it will overtake iOS (that’s iPhone, iPod Touch, and iPad) in number of app downloads.

According to the research firm Ovum, Android is expected to reach 8.1 billion downloads, this year, while Apple’s iOS will count 6 billion app downloads. Last year, Apple reached 2.7 billion downloads, while Android only 1.4 billion. That’s more than 2x growth for iOS and more than 6x growth for Android, all in just one year.

Android app downloads are expected to grow to double the number of  iOS app downloads by 2016, but even though I expect Android’s growth in all areas to start slowing down (law of large numbers), I still think it has the potential to have much more than that by 2016.

Once a platform becomes the leader and the others can’t catch-up anymore, that platform gets a disproportionate amount of 3rd party support. So even if Android ultimately only has double or triple iOS’ market share, the 3rd party support could be 5-10x bigger by the end of the decade, especially when Android really starts dominating other countries where Apple doesn’t have a very big influence, developing nations, and so on.

This is also why developers who can make their apps ad-based and free will probably reap a lot of rewards once Android becomes massive in these countries, and should make more money than on any other platform. Google is the best positioned to monetize these free apps for developers because of their relationship with international advertisers and because they bought the biggest mobile ad network – Admob.