I just released version 1.1.0 of LocalSend for Haiku, a native client written in C++ on top of the system APIs, speaking the LocalSend v2.1 protocol. It lets you exchange files and text messages over your local network with any device running LocalSend, whether it is Android, iOS, Windows, macOS or Linux. No internet, no third party servers, no accounts: everything stays on the LAN.

Devices discover each other automatically over multicast, and to send something you just drag files onto the window, or right click a file in Tracker and pick "Send with LocalSend" thanks to the add-on.
There is also share via link, so a device without LocalSend can download straight from the browser. Received files arrive with the correct MIME type already set as a BFS attribute, and you get favorites with auto accept, transfer history, PIN protection and an interface already translated into five languages. For terminal dwellers there are two command line tools as well.
All MIT, builds with a single make.
Repo and releases here: https://github.com/atomozero/LocalSend
Feedback and bug reports very welcome.