There are rumours circulating that the next software update on the 23/24th January for Amazon firesticks could potentially block any IPTV apps. I'm not quite sure how that will work but if this is true then it could cause a huge headache for many providers.
Be sure to turn the updates off just to make sure you're not affected.
http://www.aftvnews.com/internal-amazon-utility-is-mistakenly-preventing-app-sideloading-on-select-fire-tv-devices/