As expected, Apple has hit the 50 billion app downloads milestone today. The countdown that the company launched two weeks ago was updated with a new “Thanks” image on Apple’s servers earlier today, which is now publicly available across Apple.com and the iTunes Store. On Apple’s website, there’s a new photo of an iPad running Paper by FiftyThree and displaying “Thanks” as a handwritten note; on the promotion’s webpage, Apple writes “50 billion app downloads. One really big thank you”.

Apple will award an App Store gift card of $10,000 to the lucky customer who downloaded the 50 billionth app, plus a $500 App Store gift card to each of the next 50 people to download an app.

In the past five years, Apple shared various App Store download milestones: three billion apps had been downloaded by January 2010; 10 billion by January 2011; 15 billion in July 2011; for the 25 billionth app download in March 2012, Apple awarded  Chunli Fu of Qingdao, China — who downloaded  Where’s My Water? Free — with a $10,000 gift card. Apple announced 40 billion App Store downloads in January 2013, with 20 billion of them in 2012 alone.

The iOS App Store opened on July 10, 2008. After 1770 days (4 years, 10 months, 5 days), 50 billion app downloads make an average of over 28 million apps downloaded each day (28.2 million). In January 2013, Apple announced 500 million iOS devices had been sold; assuming the number jumped to 560 million after Apple’s Q2 2013 results, that would make an average of 89.3 apps downloaded for each iOS device sold.

According to Apple, “the grand prize winner will be announced soon”.