Tideroid is a free Android app developed by Serendip that provides tide information for 339 locations across Japan, including ports and harbors. Choose a location from the region list or Google Maps, and Tideroid will display the tide information for that location, including the time of high and low tide and the tide level, in a table and graph format. Moreover, the app also displays the lunar age and phase, sunrise and sunset times, moonrise and moonset times, civil twilight time, and the lunar calendar.

You can view the tide information for up to seven days by default, and clicking the "more" button in the footer will display the tide information for the following days. With Tideroid, you can also bookmark your favorite locations and compare the tide information for two different locations side by side. The app also features a widget that displays the tide information for your bookmarked locations on your home screen.

Please note that Tideroid is not intended for navigation or any other purposes that require precise tide information. The app uses the tide prediction program tide22.java for its calculations. Serendip does not take any responsibility for any accidents or trouble caused by the use of this app.