Although my county also has a weather event text message alert system that makes the ARC apps a little redundant, I like having these apps.
Their biggest downcheck is that they are dependent on having some kind of data access, either cell or wifi. Thus, if you have no data plan, and youre not presently camped out at home/Starbucks/Panera/etc, well then, you get to be surprised when the tornado blows you & Toto away to Kansas.
On the other hand, the apps provide some level of training & prep guidance.
Also the built-in on-demand sirens are good for waking the kids up.