First, you have to start PocketMetro 2.1. If you don't know how to start a Java application, you should look at the operating manual of your phone. In most phones, there is an easily accessible menu entry called "Applications" or "Games," which contains a list of Java applications available to you.

After a short splash screen, your phone displays PocketMetro 2.1's main screen:

Initially, the main menu allows you to select the start and end station of your trip. The main menu usually appears when you hit one of the "soft" button of your phone, i.e. the buttons just below the screen. In the menu, you can highlight a specific entry using the Up and Down buttons of your phone. When the right entry is selected, you can select it using the "Confirm" button of your phone. The location of the "Confirm" button varies from phone to phone. Some phones do not have a specific button: in this case, it is usually mapped to the "Call" button (which is usually labelled with a green, lifted phone icon)

Please choose the "Select Start" menu option. The "Select Start" option leads you to the station selection's screen:

Typing long station's names on a mobile phones is annoying and error prone, so PocketMetro 2.1 allows you to select a station using an index, like in a dictionary.

On the first screen, you can see a list of entries composed of a letter and a number. The number tells you how many stations in the whole network share this first letter. Using the Up and Down button, you can highlight an entry. If you press Select, PocketMetro 2.1 displays a list of 2-letters strings, where the first letter is the letter you've just selected, and the second letter a possible completion of this first letter. You have to repeat the selection until the moment where is only a few possible stations or until a given entry uniquely identifies a station. Once the list contains the name of the station you are looking for, you only have to select it and you will be taken back to the main screen. At any time, you can select the "Back" option to go back to a previous screen.

Once the start station has been selected, you must select the end station: select the "Select End" option and repeat the process for the end station.

When the end station has been selected as well, the main screen is completed:

New entries have been added to the options' menu of the first screen: "Swap Stations" and "Find Path".

If you select the "Swap Stations" option, the start station will be replaced by the end station and the end station will be replaced by the start station. This is particularly useful if you want to get a roadmap for the return trip.

When you select the "Find Path" option, the fastest path between the two stations will be computed. Computing the fastest path should only takes a few seconds. If it is taking too long, you can interrupt the search using the Stop entry in the Option menu. In this case you will be taken back to the main screen.

When the fastest path has been computed, it is shown as a roadmap from the start station to the end station.

The roadmap describes the main stops between the start station and the end station, along with the name of the line between each stops. The roadmap also shows the direction that you must take by showing the last station of the line in this direction. In some cases, the roadmap may tell you to walk between two stations.

In most cases, PocketMetro 2.1 returns two different roadmaps: the fastest one and the one with the least changes. According to the circumstances, you may prefer one or the other. If both roadmaps are identical or if the fastest one is only a tiny bit faster than the roadmap with the least changes, the fastest roadmap is not displayed.

If the line you must use has several branches, the roadmap will lead you up to the root of the branch, then it will tell you which branch to take using the next station as a direction.

You can go back to the main screen using the "Main" option.