As I said earlier on How to Hide Your WhatsApp Online Status article I like how WhatsApp tells me when my contacts seen the message sent through WhatsApp Last Seen Status Message. In some cases you may not want to reply to a particular person, or you may not want that person to see your activity on WhatsApp. You can Hide Your WhatsApp Last Seen Status on iPhone.
Well: here is how to How To Hide Your WhatsApp Last Seen Status on iPhone.
Step 1: Open WhatsApp and tap on Settings from the menu (bottom).
Step 2: Tap on Chat Settings.
Step 3: Scroll down and tap on Advanced.
Step 4: Switch OFF Last Seen Timestamp
Once toggled to OFF, your friends on WhatsApp will not be able to see when you were last online or even you are currently online.
Enjoy your Privacy!