(Also see: 10 WhatsApp Tips and Tricks Everyone Should Know)
Based on the leaked screenshots, the WhatsApp video call interface appears to be similar to the voice call one, with green-dominated tabs. The leaked screenshots show that users will also get the option to mute as well as switch cameras while on video call.
According to the website, WhatsApp for iOS version 188.8.131.52 is being tested internally, and is the build that developers and beta testers are already testing video calling feature on. So far, there has been no word on video call support officially arriving to WhatsApp but speculation has it the feature may be rolled out early next year.
Apart from video calling, WhatsApp is also rumoured to be testing a multi-tab UI which will allow users to jump from one conversation to another without going back to the main chat list. Details about multi-tab support on WhatsApp are limited as of now.
To recall, WhatsApp started rolling out voice calling support back in March with Android users. This was later rolled out to other platforms including iOS, BlackBerry, and Windows Phones. We can expect the company to start video calling rollout somewhere during the same period next year. Notably, Facebook's standalone Messenger app already supports video calls.