US East for chartplotter (aka Navionics) also does ActiveCaptain
Ship Finder for AIS
Boat Weather for NOAA
BuoyData for like it says
Wx ALert USA for land weather

Rarely use fior chart, though. Is why have the Garmin! And now the Lowrance of the radar.
Next time with dinghy in Rockland harbor at night will use! Once helped in fog at haul-out in Mattapoisett. Couldn't see the ramp and waiting taxi.

3D Compass for fun
Clinometer also fun.
Star Walk for the night sky