Apple is offering a $10,000 App Store gift card to the user that makes the 50 billionth download from its iOS store. It will also award $500 gift cards to the 50 people that buy an app immediately after the 50 billionth download has been made.

At the time of writing, the App Store is more than 750 million downloads short of the milestone.

Launched in 2008, Apple passed the 25 billion download mark in March 2012, when it gave away a $10,000 gift card to Chinese user Chunli Fu.

According to CNET, it took just 15 days for users to download around 700 million apps in the run up to the 25 billionth download.

The size of Apple’s app catalogue has increased substantially since then, with the most recent figures putting it at 850,000 titles, compared to 600,000 in April 2012.

Apple also listed its top 25 paid and free apps of all time. Rovio’s Angry Birds and WhatsApp topped the paid list, while Facebook and Skype headed the free rankings.