The launch of “wearable tech” — gadgets worn on the body — caused the biggest stir on the opening day of the Mobile World Congress in Barcelona.

WhatsApp CEO Jan Koum says the popular messaging application for smartphones, bought recently by Facebook, will soon be offering a voice service.

I DON’T know Brian Acton or Jan Koum, the founders of the $19 billion WhatsApp, so their success does not make me resentful — thankfully.

In less than five years, WhatsApp has become one of the most-used smartphone apps — with around 450m monthly global users.

Social media giant Facebook has announced that it is to buy instant messenger WhatsApp for $16bn (€11.64bn).