14 iMessage Tricks You Were Too Embarrassed to Ask
How Do I Enable and Disable Read Receipts?
Enabling read receipts means that the person you text can see when you've read their text message. This, obviously, has pros (transparency) and cons (you look like a jerk for not responding right away).
Open the Settings app, select Messages, and slide to enable or disable Send Read Receipts. Once it is enabled, the receipt will say "Read [time here]" beneath your latest text.