Read receipts, typing and last seen
The signals you send while you chat, and how to turn them off.
Kool keeps these fair. If you switch a signal off, you stop sending it and you stop seeing it from other people.
Read receipts
Open Settings, then Messages settings, and use Read receipts. The description says it straight: send and see Seen, and it is off for both sides when either person turns it off.
Typing indicators
In the same screen, Typing indicators controls whether people see when you are typing.
Last seen and online
Open Settings, then Security center, then Privacy preferences. Show last seen and online hides your activity, and if you turn it off you will not see anyone else activity either.