Apple is about to celebrate yet another landmark for its App Store. The company has posted the countdown to 50 billion app downloads on a dedicated page within iTunes. The 50 billionth app downloader will win a $10,000 App Store Gift Card, and the next 50 people to download an app will get a\u00a0$500 App Store gift card.\u00a0The gift card giveaway is open to those 13 years of age or older and located in one of the 155 countries in which\u00a0the App Store is available. Don't go into a frenzy trying to download as many apps possible, as there's a limit of 25 entries per person per day.\u00a0This isn't the first time Apple has held such contest. When the App Store crossed the 25 billionth app download in 2012, Apple awarded Chunli Fu of China a $10,000 gift card for downloading the free version of Where's My Water?. Though it didn't hold a contest at the time,\u00a0in January 2013, Apple\u00a0crossed\u00a0the 40 billion mark, adding 20 billion apps in 2012 alone.\u00a0The App Store has\u00a0continually\u00a0been a big deal for Apple, retaining its title of the largest app marketplace available. A March study from App Hero found that Apple reached the milestone of 800,000 apps available.\u00a0The study further found that 56.2 per cent of the apps on the App Store are free - a considerable amount for an online market place that has niched out its own "App Economy".Once Apple edges closer to 50 billion downloads, it will post a running countdown of app downloads. It's not clear how close the Cupertino-based company is to hitting the mark. Apple tells participants the counter is for illustrative purposes only.\u00a0Interested? You can view the iTunes page to get more information. Apple has also posted the top 25 all-time paid and free apps, including Angry Birds, Facebook, Fruit Ninja, Pandora Radio and other titles we've come to know over the years.