How to mark WhatsApp messages as unread and keep track of who you've replied to

WhatsApp has rolled out a new feature that many of us will find extremely useful.

The hugely-popular messaging app will now let you mark messages as "unread" - indispensable if you often forget to reply to your friends' messages.

All you have to do is tap and hold the conversation and the app will add a tiny green circle, switching the status of the conversation to unread.

Of course, messages inside the conversation will still be marked read - so you can't pretend to your mates or partner that you haven't seen their message.

But it will make it easier to remember who you've replied to.

The online messaging service is introducing the feature as part of a new update, along with the ability to mute conversations.

You can mute them for eight hours, a week - or a year if you really want to.

So far, the update is only available for Android phones - bad luck if you use one of Apple's iPhone models.