Last Saturday, WhatsApp founder Jan Koum went to Tickets, a tapas bar in Barcelona with Ferran AdriĆ ’s signature.

It was his first weekend dinner after signing the billionaire contract with Facebook. But the eating was interrupted by the biggest bug in WhatsApp’s history. “I went back to the hotel, opened my laptop and started to work”, said Koum to Folha.

The rare exclusive interview was given in 4 Years From Now, one of the satelitte events of the Mobile World Congress, in Barcelona, after a briefing he gave to startups and even the Prince of Asturias, Felipe.

Koum said maybe WhatsApp will cost more than US$ 0,99 in the future, after adding the voice service. And recalled the days and moments before signing the US$ 16 billion deal.