Sanytron
Sanytron builds the Astrion, a handheld remote designed around Home Assistant rather than adapted to it. It joins over Wi-Fi, runs Sanytron's own on-device interface, and is driven from Home Assistant through the RosCard custom integration installed from HACS.
Hardware availability
Sanytron sells the Astrion direct from its own store, with no dealer account required. The Home Assistant side is the RosCard custom integration, distributed through HACS and maintained by Sanytron rather than by the Home Assistant core team, so firmware and integration versions have to be kept in step.