Macworld
With iOS 18.2, Apple added a number of new options in the Default Apps section of Settings, likely in response to antitrust scrutiny around the globe. Among them are the ability to designate default calling and messaging apps, which are already supported by some third-party apps.
Now WhatsApp, which is arguably the most popular global messaging platform, supports these features.
Support for default calling and messaging on iOS is listed as a feature for the WhatsApp testflight beta, but it appears to work just fine with the latest version of the iOS app in the App Store (version 25.8.74).
To make WhatsApp your default app for calling or messaging, open Settings, scroll down and select Apps, then Default Apps. You’ll see WhatsApp as an option in the Messaging and Calling menus.
Foundry
Once this is set, WhatsApp will open whenever you hit a calling or texting interface element in iOS, such as in your Contacts or a Maps listing.
Source : Macworld
