The manual describes the use of, and options for, Journey Plotter Mobile.

Journey Plotter makes use of data from original Royal Navy and United States log-books that has been digitised and then made available by naval-history.net open_in_new.

A journey can consist of large amounts of data, so it's advisable to use a Wi-Fi connection if you're being charged for your data use.

When you open Journey Plotter for the first time, you will be asked to choose whether or not to share anonymous usage statistics.
The collected statistics will be used only to analyse which ships are viewed, and the usage figures for one or two of the application features.
If you change your mind later, you can change your preference at any time through the General section of the Settings.

Journey Plotter can be kept free of cost by showing interstitial advertisements.
You will therefore also be asked whether or not you want advertisements to be personalised.
If you change your mind later, you can change your preference at any time through the General section of the Settings.
Or, go to the General section of the Settings to make an in-app purchase to remove advertisements.