Announcing today the winner of its 25 billion App Store downloads ‘countup’, which saw Chinese iOS device owner Chunli Fu of Qingdao, China gain a $10,000 iTunes gift card, Apple’s latest figures have given us a good overview of how well its iOS ecosystem is performing.

Apple stated in its press release that there are more than 315 million iOS devices in use worldwide — a figure it originally announced in its last quarterly financial earnings call — and armed with its 25 billion download data, average download counts for users and developers can be calculated.

Dividing the total number of downloads by the number of total iOS devices worldwide means that the average iOS user downloads just under 80 applications, paid and free. This is up by nearly 18 apps from January 2011, when the App Store saw its 10 billionth download, and by 5 apps from when the App Store hit 15 billion downloads in July. This doesn’t take into account those devices that may be inactive of course, but it does give us an idea of the steady growth of the App Store.

Screen Shot 2012 03 05 at 8.43.54 AM 520x203 Apples App Store: Users install 80 apps per device, each app downloaded 45,454 times on average

With 550,000 apps available on the App Store, that means that we end up with a 45,455 average download rate per app, at least if we go by the latest statistics provided by the Cupertino-based technology giant. Obviously that isn’t the case for many developers, but it shows that some of the top earners are doing wonders for the ecosystem as a whole.

Using the same data, the App Store is currently growing at a rate of roughly 48.6 million app downloads per day. It puts Apple on track to hit 15 billion downloads per year in 2012.

Horace Dediu’s original research on the Asymco blog also helps to paint an accurate portrayal of developer income on the App Store, when compared with devices sold. Noting that developers had received $4 billion in payments until that time, he arrived at an approximate revenue per download of 23c.

Using Dediu’s ratio — which uses the average price (23c) and the payout ratio (70%) — we can use the 80 apps downloaded on average to suggest that each iOS device earns $18.40, or $12.88 after Apple’s 70/30 cut is put in place.

Apple is obviously proud of itself, recently announcing “the app revolution has added more than 210,000 iOS jobs to the U.S. economy since the introduction of iPhone in 2007,” contributing to an estimated 514,000 U.S. jobs created or supported by Apple.