After a couple of months as a free Kindle file (via this blog), for those with the time and patience to download it and put it on the Kindle yourself, The Green-eyed Monster is no longer free to download.
If you want to get your hands on the prequel to Bone Breakers you will have to buy it from Amazon. It is available for 77p from Amazon.co.uk and $0.99 from Amazon.com.
Source:
http://thegamblersnovel.com/2013/09/15/the-green-eyed-monster-2/