Sometimes, you just want to quickly create a group chat room where you can work something out without worrying about sign-ins or anything else. Hack.chat does just that and nothing you say is saved on a server anywhere.
To create a chat room, all you need to do is head to
https://hack.chat/?name-of-your-room, substituting "name-of-your-room" with whatever name you want. Then, just share that link with friends so they can join in from any browser, no download required. There aren't channel lists anywhere, so it can be used for private discussions, though it's also not encrypted or anything, so don't go sharing all the darkest details of your past. Still, as a quick and easy chat room, it works really well.