This is the first packaged release, allowing you to just unzip the archive at the root of your SD card on your Taranis X9D, X9D+, X9E and QX7. Then, just select BF as the LUA script name for one of your telemetry screens.
Please note that for the QX7, you will have to either run your own compiled version using HEAD of OpenTX 'next' branch, or wait for OpenTX 2.2.0-RC11 to be released. Alternatively, you can run BF.lua from the SD card explorer on your QX7, but be prepared for some glitches (Menu button long pressed activates some on-screen debug information).
On all X9 transmitters, please use the latest OpenTX 2.2.0RC10 or newer.