To be fair I’m not really in tune with the general public either, but every time I’ve had to link up with someone, whether old friends, classmates or co-workers they’ve always gone for WhatsApp immediately. I think iMessage is very popular, too, but I’ve never heard people mention it by name. Probably because it’s just the default iPhone-only SMS replacement.

Just to provide some perspective on the Nordics claim, since I’m Norwegian and worked in a phone store for six years. In my experience, practically no one here uses Whatsapp, except for communicating with people in other countries. It’s either Facebook messenger, Snapchat or SMS/iMessage.