We talked about RadarScope last week, which is a very good (but pricey) radar app for Apple and Droid products. For more casual weather followers who don't need fancy doppler radar but want a basic "what's it doing" outside, one of the best apps I've stumbled across on the iPad is from Wunderground. Whether or not this app continues to be as awesome as it is now with their sale to NBC and The Weather Channel remains to be seen but I think for free, it's probably the best and cleanest overall weather app out there.
One, it's commercial free. That right there makes it full of win in the free app world. Two, it gives you a combination of things that you can pull information on...from temperatures currently outside to forecasts to warning information.
The "basic" screen shot that I use shows temperatures, radar, and Philadelphia's "local" temperature. You can lock or unlock the local temperature you want to see by simply highlighting a temperature at a given site to lock it or simply unlocking it to get the temperature for the region you're scoping out. You can include personal weather stations or merely "official" ones (which I have below).
One of the cool things you can get is a forecast for a location -- either by typing in the info up top, or by scrolling around until you reach a certain location. Expanding the box on the lower right gives you the full current conditions plus a forecast that goes out several days. You can swipe to get more detail (by day or by hour) as well.
I mentioned that it will show radar and severe weather -- this screen shot shows thunderstorms over the Plains as well as heat advisories for much of that same region. The "alert" part on the bottom left will highlight your local warning if you locked in a temperature setting for one location...or if you unlock the temperature it will show it for the region you are looking at. All types of warnings will show up -- from heat warnings to severe weather, winter storm, everything in between.
The phone versions that Wunderground has out there aren't as comprehensive as the iPad edition -- I have the droid version on my phone and it's nice...just not as "good" of a weather app overall for one selfish reason. I would like to be able to shut off personal weather stations on the droid (hint hint), a feature that I utilize on the iPad. Other than that, the droid version is very solid (and again, free and for now without ads).
The only concern I have is what NBC will do to the app once their purchase of Wunderground is complete. Does ad creep take over a relatively pristine environment in the name of trying to get a few bucks or does this app continue to remain a great resource for weather information if you're out remotely or just browsing at home. In any case, if you haven't downloaded this app for your phone or iPad, do it...it's great.