Also, read | How to Use WhatsApp on Your Tablet, iPad, Windows PC, and Mac
Steps to Use WhatsApp on Apple Watch
The app which I am going to use here is not related to Apple or Facebook by any means. It is a third-party app made by some developers to help you guys out. You can just skip on this and wait for the official release from the publisher. Of course, if you are concerned about your privacy then you should take care of what permissions are you allowing to this app.
Wrapping up
This app uses the web service from WhatsApp to show your chat on your Apple Watch. So, to keep using WhatsApp on your watch, you have to keep your phone connected to the internet all time. This is a nice tweak from the developer of this app. For more such tips and tricks, stay tuned!