Aenigmatis offeres AES-256 password-based encryption to your text.
The process:
• Type, tap, and the encrypted message is in your clipboard.
• Copy the encrypted message, go to Aenigmatis, and the text is decrypted for you (set up the password beforehand).
• Also comes with an awesome keychain to save your passwords.
Other perks:
• Compatibility: Runs the open source CryptoJS library under the hood.
• Audio and haptic feedback
• iPhone X & SE Support