Regarding a smartphone app, I use OnGuard. Actually bought this one - for about $2, based on a recommendation from a fellow RVer on this forum. It works VERY well. Been using it for about a year now - it's been doing its job from the East Coast to the Left Coast. Using the phone's GPS, it alerts for whatever county you are in. ONLY drawback is it is limited to exactly where you are, not what may be headed your way... I still have and use a regular weather radio in the camper. This alerts for whatever counties are in radio range. I do not use SAME codes when I am on the road. When I am concerned about threatening weather, I check my paper maps (just 'cuz I have GPS, etc., I STILL carry paper maps...), and note the county I am in, plus surrounding counties, usually to the west/southwest, since that is "usuallY" where storms move in from. So when it alerts at 0-dark-thirty that XYZ county has a severe weather alert, I can quickly know if I am in the "line of fire" and need to beat-feet or hunker down, or just go back to bed. Cheap insurance in my opinion. ST