An iPhone read receipt is the Apple equivalent of WhatsApp’s blue checkmarks. They show someone on iMessage that you have viewed their message. However, this feature may annoy you because you may not be ready to respond, or you may not want to respond. So having your phone tell the other person you’ve seen the message, then ignored it, may cause some unintended friction. Here is how to turn iPhone read receipts on and off, for both everyone and for only specific people.