> Without WhatsApp support it will not go far.

Speaking of which, it is bizarre how the tables have turned. Whatsapp used to support everything under the sun... But now it is all Android and iPhone

They could do Telegram at least, which has a non-zero user base (not sure about India, though, which seems to be their target market), and supports third party clients. Rolling their own chat app is... well, good luck with that.