As we approach Apple’s 2016 Worldwide Developers Conference, it is increasingly apparent that mobile has become the first screen. Markets are maturing and how consumers habitually use apps is now an important consideration for publishers’ monetization strategies. Usage is increasingly becoming the new standard currency for app developers, as opposed to revenue — so we took a look at the most used iOS apps for April 2016. We also dove into MAUs and usage penetration year over year in the United States, Japan and the United Kingdom.

Below are some key highlights from this report:

• While gaming apps will always be a staple of the app economy, social networking and communication apps dominated across international markets for monthly active users (MAUs).

• Apps catering to regional preferences saw the biggest gains year over year in usage penetration. And apps supporting wearables, retail and ride-sharing saw strong growth as well.

• In the US, Facebook tops the charts for most time spent in-app by users, with Snapchat following closely behind — and music streaming apps are also well-represented in the top 10.