The app is Clime Pro on iOS, they lock full access to Hurricane Milton data behind a $10 USD per week paywall.
If you’re in the area impacted by Milton, you can find publicly available resources at the National Hurricane Center’s website: National Hurricane Center
For anyone who doesn’t know where here’s NOAA. https://www.nhc.noaa.gov/refresh/graphics_at4+shtml/093335.shtml?cone They’re who does America’s atmospheric and oceanic measurements, everyone selling it gets it from them