Below is a link to Pro version 1.1.11.1.build.10111112 which I uploaded.
Doesn't have to be custom anything. It basically emulates a MAG device (and a few others), and you can use it with "nearly" every iptv provider which supports MAC based subs. This is NOT for M3U based subs.
I can't comment for a firestick, but it works perfectly on a generic el-cheapo android box, and a few others which I have (Mii Box, and Beelink GT1). Nowhere near the experience of a buzz box or similar box (like the Formuler Z7+), but it does the job.
Code:
http://www.filedropper.com/se1111