APPS:
Consult your Apple or Google app store.
My Radar
Real time weather radar info.
Windfinder
Wind, temps, tides, wave heights and precipitation all in one place.
Tide Charts
Tides, weather and radar
Weather Bug
Free or paid premium products
Navionics
Nautical and fishing charts
RadarX
Real time radar
NOAA
Various apps available
Isailgps
Allows free downloading of RNC charts
Animatedknots.com
Not an app but internet tool