Even though it's the main feature, NOAA Hi-Def Radar isn't just for radar images. You can drag and drop a pushpin for local weather to any location to see the current weather there, along with a five-day forecast with basic information. There is also a system for bookmarking locations so you can quickly switch to favorite spots to see what the current weather outlook is there. As far as customization is concerned, you can adjust which colors are included in the weather severity spectrum, and several other options from the settings screen by touching the gear icon in the lower right.
One big missing feature
The only thing I think is missing in NOAA Hi-Def Radar is sending weather alerts in severe weather conditions. The app is great if you look at it before the storm arrives, but if it could send you an alert when severe weather enters your vicinity that would be extremely useful. It seems like a pretty easy fix since it already knows where the storms are and it clearly uses GPS to pinpoint your location, so why not send an alert when the two get close together? It would also be useful if it could warn you when severe weather is approaching a bookmarked location as well (I'm imagining an alarm for when a storm is approaching a friend or family member, for example). The app has a link to a separate app to get these features, but I really think it should be part of NOAA Hi-Def Radar.
Overall, NOAA Hi-Def Radar is great for fast-loading weather radar maps and several other features, but if it went the final step of sending your phone proximity notifications, it would be the perfect severe weather app.