If you have international family/friends, WhatsApp is the most ubiquitous and easy to use option I’ve come across.

Honest question: Is it really? That can be just my network, but I've never stumbled upon anyone using WhatsApp here in Poland. I only know this name because I follow tech news. Almost everyone uses Facebook's Messenger, some people use Telegram, sometimes Hangouts, gamers use Discord, techies Signal or Jabber and that's pretty much it.

Of course, my observations are limited to me and I don't have any numbers. My interactions are with people in Brazil/US/UK/Australia/India/South Africa/Kenya/Spain/Central America.

I know WeChat is more popular in East Asia, and I know a few Telegram/Signal users, but I can find about almost everyone on WhatsApp.

When I was in the Nederlands last year they actually had public signage advertising a WhatsApp group chat (for emergencies and the like) for the surrounding community.

I was surprised by how popular it is.

I'm from Brazil, live in the Netherlands. Whastapp is ubiquitous in both places. Not using it today is akin to not having a mobile phone years ago.

My friends from Germany, Switzerland, and France all primarily use WhatsApp I've no idea why.

And why alternatives like Telegramm are not an easy to use option?

That might be an option, but not as ubiquitous and easy to use. We’re dealing with people who barely read and speak a single language, much less English.