Soon after Android users began reporting the rollout of the WhatsApp free voice calling feature, iOS users with the latest version of the app are now reporting the presence of call buttons.

The two new call buttons visible in the WhatsApp iOS app (v2.11.15 - currently available on the App Store) for now only bring up the standard iPhone dialler, rather than placing a VoIP call through WhatsApp. This should change when WhatsApp finally rolls out the functionality.

One button, near the contact name within a chat conversation, features the phone symbol, while the other is present on the left side below the top pane, and reads 'Call'. The new buttons are definitely a new addition to the interface, and seem to be independent of the regular call feature via the dialler, which is still accessible when the user opens a contact's info page and navigates to the phone number.