|WhatsApp. source: detik.com|
Quoted by the Times of India, on Monday (07/25/2016), both of these features is so far not been released on Google Play Store, but is available in the latest beta version of WhatsApp app.
WhatsApp for Android beta version 2.16.189 put both of these features below the call log WhatsApp. Option voice mail and call back can be seen when a user does not lift a phone call WhatsApp.
Two of these features make it easy for users to contact the person to call back. Especially for the voice mail feature, shown as a voice message as usual by the receiver.
How to use it the same as usual when it will record a voice message, tap and hold the microphone icon and then speak. It's just so much easier to use as they are displayed on the same screen.
Good features voice mail and call back at this time can be downloaded manually via APK. Not yet known when WhatsApp will release it officially.