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
nhc.noaa.gov is the best for quick, up to date official info about expected impacts. Also local county and municipality pages are important to check for evacuation orders and routes.
For anyone who wants technical deep dives into the meteorology of tropical storms, I can’t recommend tropicaltidbits.com enough.