The RainToday Smartphone app is really useful too. It gives a prediction of when rain is due for your location and how long it's going to last.
I've been using the "Dark Sky" app for a couple of years, sounds similar to The Rain Today, gives a 24 hour forecast for current position plus detailed rain for the next hour. It uses weather radar and is surprisingly accurate. Particularly useful if you're parking and can't decide if you need to cover the car.
