Smartphone users will download nearly six billion apps this year, according to a new report published by ABI Research.
That's up from an estimated 2.4 billion in 2009, fuelled by increasing sales of smartphones and the launch of new app stores.
ABI thinks Apple's iOS will account for more than 3.3 billion downloads this year, while Android will generate 800 million downloads.
"The iPhone will continue to be the leading app platform, with a database of over 125,000 applications offering niche and localised content," says analyst Bhavya Khanna.
"Other platforms are still playing catch-up, with Android being the fastest gainer among them."