There has been reports and leaks on the highly anticipate voice call function in WhatsApp since their CEO announced this in last year’s MWC. Recent report has shown that Android users are already able to try it out right away on their phones as soon as they install the latest build apk (v2.11.561). There was also good news for Windows Phone users. On another hand, iPhone users are yet out from the party.
But you are lucky if your iPhone is jailbroken. There is a new jailbreak tweak called WhatsApp Call Enabler that allows you get the taste of the unreleased feature right now before an official update. But it is not on any of the default repos. What you need to add the developer repo http://apt.imokhles.com in Cydia and install it. The latest version of the tweak is 1.0-2 by the time of this post.
After installation, you have to enable it in the settings panel in the stock Settings App. Make sure you kill the WhatsApp or you will not be able to get it working.
After restarting, you will see a phone icon on the top right hand corner beside the profile picture of your friend’s contact that you were not able to find before this tweak. Tap it to call them right away! However, you will be only able to call users with versions of WhatsApp that supports Voice Call. If not, you will be prompted with a message stating that the person you are calling needs to update the app in order to receive the phone call, like my secondary iPhone number shown below:
I personally tried it out and I was able to get it working well (testing device: iPhone 6, iOS 8.1.2). I have also have CallBar and WhatsApp+ installed without any issue or interference. Let me know in the comments if you also succeed in getting this work.
Disclaimer: YMMV, I am not responsible if it does not work on your iPhone