To stream New York Knicks game broadcasts on your iPhone download the TuneIn Radio app. Then trying going to the New York Knicks local flagship radio station feeds for live gameday streaming as well as pre and post game shows.
In the Tunein app, do a search for "New York Knicks" to get the Knicks radio network stations. Or search for the flagship Knicks station: 1050 ESPN New York. If the play-by-play is not streamed by the Knicks station, then try a search for the Knicks current opponent team name so you'll be able to still listen to the game for free.
You may also want to check out the NBA Game Time app, and then get the in-app purchase of NBA League Pass, which allows you to watch all NBA games live.