If you're a subscriber to TimeWarner cable they have a free iPad app that lets you watch your favorite cable TV shows like the NBA finals on ABC directly on your iPad called TWCable TV.
You can listen to the NBA regular season games, as well as the NBA playoff games using the TuneIn Radio app.
Also you can listen to the NBA finals on your iPhone, iPod Touch or iPad, you'll want to download the NBA's official app called NBA Game Time app which offers you the ability to stream home and away radio broadcasts of all the NBA games once you upgrade to Game Time Plus.