When most people think about apps for watching live sports on their phone they think about subscription services like ESPN and Sky Sports. The good news is Yahoo Sports have completely revamped their iOS and Android app to include live steams of hundreds of Major League Baseball (MLB) and National Hockey League (NHL) games. The best part is you don't need a subscription. Many games will be streamed "Live on Yahoo" so you'll be able to watch them from your iPhone or Samsung Galaxy without leaving the Yahoo app. Yahoo have also cleverly developed a live sports streaming guide that will tell you where you can watch additional games for free. Hockey fans can currently watch 4 live NHL games via the Yahoo Sports iPhone and Android apps completely free of charge. Yahoo also acquired the rights to stream 180 MLB games via mobile so you'll always have a game to watch. Android - https://play.google.com/store/apps/details?id=com.yahoo.mobile.client.android.sportacular iPhone - https://itunes.apple.com/us/app/yahoo-sports-your-teams-your/id286058814?mt=8
If you want to watch NFL games for free you should download the Twitter app for AppleTV, Xbox or Amazon Fire. Our discussion thread on the best NFL iOS/Android apps might also provide you would some tips on other useful app.