How To Read WhatsApp Chats Without Triggering The Blue Double Check Mark

Install the “Unseen – No Last Seen” app on your Android mobile. (Click here to download the app)
On the first launch of the app, it will show you an intro. Swipe left until you see the “ENABLE ACCESSIBILITY” button.
Tap on the “ENABLE ACCESSIBILITY” button (Notification access settings will open)
Check the “Unseen” checkbox.
Now read your WhatsApp chats through the Unseen app.

That’s it; Blue double check mark won’t trigger when you read your WhatsApp messages through “Unseen – No Last Seen” app.