I don't think NOAA will have an official App until 2020 but I have been using this app for years:What weather app would you recommend?
Weather.gov/Noaa
Accuweather
Weatherbug
Weather
WTForecase
KCCI
Foxnews
Cnn
https://play.google.com/store/apps/details?id=com.nstudio.weatherhere.free&hl=en_US
It takes the local NWS data into an easy to use form. The radar is not very good though.