Developers have made more than $9 billion from Apple’s App Store, with half of the total coming in the most recent four quarters, the company revealed in a conference call this week.

Peter Oppenheimer, the company’s CFO, revealed that during the first quarter of calendar 2013, the App Store catalogue hit more than 850,000 iOS apps, 350,000 of which are designed for the iPad.

Cumulative downloads passed 45 billion during the period.

There are now App Stores in 155 countries covering almost 90 per cent of the world’s population.

Oppenheimer attributed the dominance of the App Store to “the great development environment, broad distribution, large and active user base, and seamless integration that the iOS platform offers”.

Apple also announced that its 2013 Worldwide Developers Conference will run from 10 June until 14 June 2013 in San Francisco. Tickets go on sale on 25 April.