With around two billion users, WhatsApp’s incorporation into the Facebook empire looked to have cemented its status as the market leader for messaging. But over recent months, the app – though still massively popular – has actually seen numbers dropping. As our guide discovers, though, the exodus may have been an over-reaction. We’ll also check out the other new features WhatsApp’s introduced. Why should parents and carers be aware of the ‘disappearing messages’ option? What has the app done to arrest the spread of fake news? And how does it help young people to start thinking more critically about things they might read online?