What weather app reads weather alerts to you?

I was in the dentist today and this ladies phone went off and said "A tornado watch has been issued for your area" Her phone was in her back pocket. I want to know what app this is so I can download it. She had an IPhone. I was going to ask what it was but before I got a chance they called her in the back.

It's more than likely the WEA (Wireless Emergency Alerts) that gets pushed to the phone by her service provider, not an application on the device itself. It's sort of the same thing that happens when your television broadcast is interrupted by a public service/emergency alert announcement. I get those alerts on my iPhone through Sprint even though I never downloaded an app.

Here's the National Weather Service list of third party alert providers you could try:
https://www.weather.gov/subscribe