Russia: Telegram
Taiwan: Line
Japan: Line
By contrast, WhatsApp is best known to me for being used in Europe, Australia, and India.
For business comms drop instagram and move WhatsApp to first.
For Singapore it seems LinkedIn messages are the go to IM for business.
Europe p2p: telegram number one by a huge margin, then WhatsApp. B2b: WhatsApp, period.
Russia: Telegram
Taiwan: Line
Japan: Line
By contrast, WhatsApp is best known to me for being used in Europe, Australia, and India.