The most effective and easy to use website is in the market. They broadcast all nfl Preseason and Full season live games. Streams are wowza based ABR + their android app is easy to use and very reliable. In 39.99 USD for season you can enjoy all games in High definition. The streams work all around the world. They also offer free 7 days package so you must hurry and book your package before they close the signup for the season.
Main website: https://nflstreamsonline.com/nfl-live-stream-online/