YouTube was the subscription app leader across both Apple and Google app stores, earning $991.7 million in gross revenue globally and $562 million in the US alone.

According to data provided by app analytics firm Sensor Tower, revenue from the top 100 earning non-game subscription apps represented about 11.7 per cent of the $111 billion that consumers spent on in-app purchases last year.

According to Sensor Tower Store Intelligence data, in Q4 2020, 86 of the top 100 earning non-game apps worldwide offered subscriptions, down slightly from 89 in Q4 2019.

"Consumers have historically spent more on the App Store than on Google's marketplace, and the same holds true for subscription apps," the company said in a statement on Thursday.

Globally, the top 100 subscription apps on the App Store generated $10.3 billion in 2020, up 32 per cent from $7.8 billion the previous year.

The cohort of 100 top earners on Google Play saw $2.7 billion last year, up 42 percent (on-year) from $1.9 billion in 2019.

Alphabet came out on top this year in terms of subscription app spending, both globally and in the US.

YouTube was also the top earning subscription app on the App Store, whereas Google One was the top-grossing app on Google's marketplace with more than $445 million generated globally and $255.7 million in the U.S.

The report found that mobile game publishers were adopting subscription models at an increased rate in 2020, with eight of the 15 top grossing titles offering recurring in-app payments.

"This shift in strategy follows consumer trends — even before the COVID-19 pandemic, consumers have been spending more on the top subscription apps than in the past," the report said.

From Q1 2019 to Q4 2020, US consumers spent more in the top 100 subscription apps each successive quarter. This cohort of apps saw $1.7 billion in the final quarter of 2020, up 31 per cent from $1.3 billion in the first quarter.