iOS has had the ability to hide your last seen from friends for a while now. If you were an Android user, this was something you could not do unless you went with a client like Whatsapp Plus. However, just a day after being bought out by Facebook, Whatsapp for Android has been updated with privacy settings which allow you to hide your last seen, your status message as well as profile picture from everybody. This is a handy update as it keeps the stalkers who have been using the information from Whatsapp profiles for wrong purposes.
The latest build of Whatsapp that brings the update is not available on Play Store just yet. To get the update, all you need to do is to visit the official website of whatsapp and download the latest apk from here. Once you have the apk, transfer it to your phone and go ahead and install it like any other app. It will over ride your previous application without any modification.
Now, under settings, go to Account and from there under privacy, you will see three options of hiding your last seen, status message as well as profile picture. You can also pick the option of displaying all three to your friends which are in your contact book and not anyone else.