One-Time Secret - One-Time Secret is a way to share sensitive information simple and secure.

nohistory.fyi - nohistory.fyi is free to use webservice to share secret messages in a secure way.

Privnote - Send notes that will self-destruct after being read

1ty.me - If you need to send a password or some other form of simple but sensitive information to someone...

Yopass - Yopass is a project for sharing secrets in a quick and secure manner*.

SafeNote - Encrypt and send files and notes with a link that automatically destruct after being read. SafeNote is a free web-based service that allows you to share a note or a file with confidentiality. There is no way to spying on you even to a hacker.