It is not clear what you mean by "local TV." Local TV is television that it available free over the air to all viewers who have a tuner. It is also locally-produced cable content such as a local cable news channel or public access cable channel. The Mac application for viewing such programming is elgato's eyeTV 3. Be mindful that the software must be combined with a tuner such as elgato's eyetv 250 plus, which can receive all free broadcast and cable TV programming, whether analog or digital, in the US and Canada.
If you have TimeCableWarner at home you can download an app and watch it on your iPad too. The only issue is you need to be on the same WiFi as it to view. Still, its incredible. Very clear. You could also try hulu via Safari