while WhatsApp is the largest I am aware of (it's one of the leading platforms W...

while WhatsApp is the largest I am aware of (it's one of the leading platforms Worldwide anyway), there are quite a few, sometimes in the form of Elixir:

- Discord

- Pinterest

- Spotify

- Klarna

- Riot games (the messaging service)

- PepsiCo (for their billion making e-commerce)

- Toyota (for the connected platform)