I need you guys to use it, so fun during events year round! Nothing better than ground truth obs you can zoom around the entire country. The project is suppose to help with precip type and determining if its just virga! Would be awesome to see real time reports change from south to north during a warm nose lol. The NWS does use it and will see what you are reporting. Sometimes it gets shared to Facebook.
I use the weather channel, storm (weather underground) both free, and also radarscope which is $10.
The others are ok and do have alerts but their maps are a little off and don't update until about 8-10 minutes past current time, so if it's 1:30 you're looking at the 1:20 map which always bothered me when I was right in the middle of something. The weather channel also offers a 6 hour forecast radar so you can get an idea of where the storms are headed.
If you can spend the $10 I highly reccomend radarscope as it is incredible and puts all of the professional tools in your hand. You have reflectivity, velocity, correlation coefficient, and much more. It also updates every 2 minutes. The one and only complaint about that app is that it uses radar sites, so you have to pick one and can only see as far as that site sees. So, if there is weather in north ga for example I can't use the warner Robbins radar, I have to switch to the one closer to Atlanta to see the system. It's a little aggravating but it's so feature packed that it makes up for it. Having that app has greatly reduced my lilapsophobia as I have a much better picture of what's going on in the storms now.
I use the 48 Weather app which is free and offered by our local NBC affiliate. The alerts are configurable, it offers map layer control, etc. I'm not sure if or how well it works outside of this area, but a friend in Denver, CO uses it. He says the lightning detection does not work for him in Denver, but that's the only issue he has mentioned.