As I understand it, it's an app that would work with an android smart phone that would allow you to use the phone to generate a wifi hotspot which you can then use to let other devices -- say, a Kindle with wifi only -- connect. It is NOT an app that you'd load on your Fire because the Fire hasn't got the capability to either connect via the cell network (except for the 4G8.9) nor the ability to re-broadcast the signal. Not even all smart phones will.
It may be available on 1Mobile, probably also on Google Play.
It may be available on 1Mobile, probably also on Google Play.