I wanted to make something like this, but using Bluetooth LE. Then I looked at the Bluetooth spec and implementations realized why Bluetooth applications are so unreliable (other than Apple device to Apple device). It’s really hard. Plus every OS has their own incompatible API, with some parts missing or inaccessible for some reason.
The practical solution to “share files in physical proximity” ends up being just use Apple everything.
The practical solution to “share files in physical proximity” ends up being just use Apple everything.