If you own an iPhone, chances are you’ve used the Messages app at least a few times. In fact, it’s probably the most used app on your iPhone.

There are a lot of great things about iMessage that make it an ideal messaging platform, like the fact that it’s completely encrypted and works over the internet. But Apple’s free service has some quirks that are helpful to know about. It also has features you may have never used before.

First, do yourself a favor and turn off read receipts.