WhatsApp

ThoughtStorms Wiki

Context : ChatApps

Now part of FaceBook. So I wouldn't use it.

But horrifically popular.

Nevertheless, this story https://entrepreneurshandbook.co/ukrainian-developer-built-a-19-3-billion-app-because-silicon-valley-was-too-ignorant-to-do-it-24a5b83f8fa8 explains its popularity and what was good about it.

Famously built in ErLang