I disagree. The github repo he links to in this writeup contains everything necessary to install a custom firmware to the Fitness Band. He even includes the bin

I disagree. The github repo he links to in this writeup contains everything necessary to install a custom firmware to the Fitness Band. He even includes the binary itself, which is probably not too smart(it would have been better to write a script to download the binary direct from MS's server). What more do you want? Cydia?