This comes straight from Kryptos’s own GitHub page, and it’s free. Need help installing?
What it looks like
About this app
Kryptos lets you encrypt messages without ever leaving the messaging app you're already using. It works as a keyboard: type your message, it encrypts it, and the other person's screen decrypts it back, so there's no separate app to jump into.
It uses the Signal Protocol for strong end-to-end encryption and works completely offline. Kryptos is available for both Android and iOS.
From the app’s home page
- See the codeHow it’s made, every line is public
- WebsiteThe app’s own home page
- Questions & commentsTalk with the people who make it
- Report a problemTell the makers something is broken
- All versionsOlder downloads and what changed
- LicenseThe rules for using and sharing it
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