I would skip the WhatsApp. It’s trash. Fight me hundreds of million people for whom WhatsApp is the de facto standard for instant messaging and calls.
FTFY. I was in Bali this summer, everyone uses WhatsApp. Spent three days in an upscale hotel, on the check-in form they specifically ask for your WhatsApp number, which they use for everything: room service, special requests, restaurant and spa bookings, ...