Users of Google's Android operating system will spend $41 billion in total on apps and subscriptions in 2017, topping $40 billion for Apple, a new report has found.

App Annie, which focuses on data related to the mobile-app ecosystem, projected that Apple would still have the most dominant single app store.

Apple's App Store racked up $34 billion in sales in 2016, while Android apps collected $27 billion, a report in MarketWatch website said on Wednesday.

Although Google has its own Google Play online destination for apps, there are several third-party offerings for devices that run on the Android operating system.

App Annie projects that revenues for Google Play and third-party Android offerings will be roughly similar with $21 billion in Google Play revenues and $20 billion for other offerings, the report added.

Another reason for this might be the number of devices used.

Android should be expected to outpace Apple because Android devices outnumber iOS devices by about a 5-to-1 ratio worldwide, Danielle Levitas, Senior Vice President of research for App Annie, was quoted as saying.

"So there's much room for movement and while this shift might happen in 2017, ultimately, we forecast the App Store remaining the most lucrative store in the next five years," Levitas said.

According to market research firm Gartner, Android had more than 80 per cent of the smartphone market share in 2016 while iOS was at 17.7 per cent, yet Apple routinely takes a majority of global profits in selling its devices.