WhatsApp Tips and Tricks Everyone Should Know
Mute group chats and notifications
Read receipts, marked by two blue ticks indicate that the recipient has read your message. Find out who has read your message on group chats.
Do a long press on a message sent by you. This reveals an 'i' with a circle around it. Tapping on it will show you who the message was delivered to, and read by.
See the Message Info screen by opening a chat with a contact or a group, then swiping your message from the left to right to see delivery and read notifications.