Check out PlayStation Vue (works on Playstations, Amazon Fire, Rokus, and Chromecast). It contains the regional Fox Sports channels, ESPN channels, and NFL Network. You can add the RedZone for $40/season. Prices start at $30/mo. I made the switch and couldn't be happier.
Web Video Caster was made for this. Install and then when you have nfl2go pulled up in browser just share to and Web video Caster will be an option. https://play.google.com/store/apps/details?id=com.instantbits.cast.webvideo
Roku is a device you plug into your tv to stream video content. It has "apps" for things like Netflix, Hulu, Amazon etc. so you can play their content on the TV it's plugged into. NFL2Go has an app as well that enables you to watch the streams of the games on your TV.
In the UK, nothing working without a VPN routed through the United States.
Highly recommend AirVPN, getting full speed for NFL Network, €1 for three days of access, hopefully the service is fixed for international users by then.
If you're having issues you can try this app they suggested in one post, is pretty cool, just use the direct link on it:
https://play.google.com/store/apps/details?id=com.instantbits.cast.webvideo
The easiest way to cast is just using the html5 player or native one and use the cast icon in the player itself. (for live games use the green one). You must be on the same wifi, it won't work if you use the nearby devices functionality in your chromecast.
Note: Yellow streams are only available in Europe.
if the native player doesn't work with your CC, give this app a try from your android device. works great for me: