WhatsApp is rolling out a big update this week that reintroduces a new way to tell the world what you are up to. It's called About and those who have had this chat application installed on their phones for a while might remember it from before. WhatsApp say it's bringing it back to allow users to quickly share what's up in their lives.

"Today we're reintroducing and improving About, making it more visible, timely, and easier to use," the chat app said.

So what is About all, err, about?

This upgrade is aimed at those days when users are free one minute but busy the next.

About basically lets those with WhatsApp tell others why they can't talk or what they want to talk about with just an emoji and a short phrase which appears at the top of the chat box.

"About will now be easier to spot at the top of 1-1 chats and on your profile," WhatsApp explained.

"You can also reply directly to people's About by tapping on it in a chat. About will expire after one day, but you can also choose for it to disappear faster or keep it around for longer at a time of your choosing. Just go to Settings and tap 'Set About' to choose your timer."

Users can decide who sees their About. It's easy to set to be seen only by contacts, or choose to make it more widely visible in the privacy settings.

WhatsApp says it is rolling About out to everyone on mobile starting this week.