Apple and Google saw their respective mobile app shops thrive as the Silicon Valley giants remained under fire for the power they wield at their respective marketplaces.

Preliminary figures indicate that US$64.9 billion was spent across the App Store and Google Play in the first six months of this year, in a 25% jump from the same period last year.

Sensor Tower projected US$41.5 billion would be spent at Apple’s App Store during the first half of this year on subscriptions and apps, including in-app purchases such as virtual items for game characters.

Google Play was expected to generate a total of US$23.4 in revenue by the end of this month.

TikTok was the top grossing non-game mobile app, with users spending more than US$920 million in an increase of 74% from the first six months of last year.

YouTube was the second biggest non-game revenue generator, with users spending US$565 million there, the market tracker estimated.

Globally, spending on mobile games hit US$44.7 billion in the first half of this year, up nearly 18% from the same period last year, according to Sensor Tower.

Chinese internet titan Tencent had the top grossing mobile game, “Honor of Kings”, which generated more than US$1.5 billion in the first half of this year, according to the market tracker.

‘App economy’

The survey shows the growing importance of the so-called “app economy” and comes amid criticism over the tight control of the two large marketplaces by Apple and Google.

The Sensor Tower figures were released as a federal court mulls evidence presented during a trial in which Epic Games is trying to break Apple’s tight grip on its App Store, and potentially disrupt the entire mobile ecosystem.

Epic, maker of the “Fortnite” video game, is seeking to force Apple to open up the App Store to third parties seeking to circumvent Apple’s procedure payment systems and its commission as high as 30% in the process.