I rate this book 5/5 stars for the sheer tragedy of it. It says "here is a missing story that has been waiting to be heard," and then proceeds to remind you that  the capitol (translated: those in power) takes everything, is responsible for every death, every tragedy, and even after the hunger games have ended, you can still see the effects of their cruelty. 
This was very well-written, very well thought out. I found myself pausing to consider just the word choices used. The ending made me cry and the epilogue was poignant