CryptoTE - CryptoTE is a text editor with integrated strong cryptography.
Milanote - Milanote is a note taking app for creative work.
Paranoia Text Encryption - Paranoia Text Encryption encrypts text according to a choice of strong algorithms.
Efficient Diary - Efficient Diary is an elegant, easy-to-use and powerful electronic diary software package.
VeraCrypt - When you need to know that your information is secure, VeraCrypt offers an added layer of protection. Their encrypting process keeps your files and data safe from prying eyes.
Swiftnotes - Swiftnotes is a note taking app that takes simplicity and speed to a whole new level.