Also, for Android in general, several good tide apps. I use Tide Chart free
version. It allows you to set 3 favorite ports
and get daily high and low tides for each, plus a graph of all tides for days ahead that you can simply flip through. You can also input any lat/long and get tides for that place. You can set a future date and see tides for next month or next year.
And other cool apps --
(no 3G needed, unlike Google's star app). Point it up to any spot in the sky and it shows you the names of stars and constellations. You do need to have GPS and an inclinometer on your device.
-- gives you sunrise/sunset, moonrise/moonset, moon phase, length of day compared to shortest and longest day of the year, rise and set times for all planets, azimuth of sunrise and sunset, azimuth for moonrise and moonset, noon elevation, etc .
-- shows direction and strength of winds for any location.
Still looking for a good app that shows significant currents.