Stay current with U.S. coastal tide predictions. This app gets the latest tide predictions from NOAA. Tidecast also displays sunrise, sunset, and moon phase, and covers over 2,900 stations. Comes with a handy homescreen widget.
NOTE: If you move the app to your SD Card, you will need to reboot to re-enable the widget! You can move it to your SD Card on devices running Android 2.2 (Froyo) or newer, under the "Applications -> Manage Applications" section of the Settings app.