How to remove yourself from a group text or mute the ones you can't leave

Unless everyone is using iMessage, there's no way to remove yourself from a group text — you'll need to mute or block it.

How to make a group chat on Snapchat, to send private Snaps and messages to multiple people at once

You can make a group chat on Snapchat in a few taps to send pictures, videos, and chat messages to a select set of people at once.