sup3rS3cretMes5age - A safe, simple tool for one-time (self-destructing) messages
MagicPad - Free, simple, and private, offline text encryption suite.
BURN.link - Send secure, encrypted, self-destructing messages
Signal - Fast, simple & secure messaging. Privacy that fits in your pocket.
Boop - A scriptable scratchpad for developers. Free & open source!
Blur - Blur is a software application available for both Google Chrome and your smartphone. It's developed by Abine, an online privacy company trusted by more than twenty million people. Read more about Blur.