Hi, author here. No. Not using Bluetooth LE, since there is no support for acting as a "server" device that can be discovered by other peers. It's sure to come

Hi, author here. No. Not using Bluetooth LE, since there is no support for acting as a "server" device that can be discovered by other peers. It's sure to come someday, but right now it's only possible using a rooted phone. It maybe possible that Firechat uses either Wifi Direct, which is supported on most modern Androids or classic Bluetooth, although the discovery/connection requires user interaction.