WhatsApp latest version is not yet available on PlayStore. ToActivate this feature, you have to download latest version from WhatsApp official website .
Not only this, another new feature is the Custom Notifications which will be seen below the Media section of your chat settings, along with mute chat. Custom Notifications option lets you select tones, vibration length, light, popup notifications, call ringtone, among others.
* To enable this feature, download it from above link then just Tap & Hold your friend’s chat and enable it from pop up menu. Hope you loved this awesome feature of WhatsApp. Do share with friends and let all enjoy this superb update.