> Uses only modern cryptography, with formally verified implementations.

That's a bit light on details. Does it have hardware acceleration? Replay attack protection? Perfect forward secrecy? What are the underlying algorithms? Implementation verified by whom?

> Small (~25 KB), with an equally small and readable code base. No external dependencies.

This looks cool, however I don't like the fact that it doesn't use a trusted crypto library such as libsodium. It is likely to get less review and if weaknesses are detected in the algorithms, it is less likely to be improved.