Some good comments on cryptography that I will probably bookmark and use to study in the future, but as an end-user, I've been hoping for years on a local-network-only solution that basically works on all platforms. Functionality-wise, cryptography can shape up in time whereas I can use these non-trivial features today. Bravo for the privacy-conscious approach and development of apps closer to native. I tested it in these directions and double checked with sha256sum:

- Mac <==> Mac (Wireless)

- Mac <==> Mac (Thunderbolt 4 Bridge)

- Mac <==> Android

- Mac <==> iOS

- iOS <==> Android

Features I'd have interest in:

- Choose interface/IP address to listen on by default instead of all interfaces (can still be first-time default). This helps prevent accidentally sending over a not fully-trusted network. I imagine that with the next iPad supporting Thunderbolt 4, it could be easy to send over wire. This also helps smoothen someone's lack of confidence in the network security of the app. You also probably already thought of this since there is an "Advanced" section which currently supports changing the port

- Have some way to verify the target's IP address for the Flutter app on iOS and Android prior to sending

- A command-line interface to automate sending and receiving

- A way to donate if you're open to that

(@yvbbrjdr go bears!)