The Free Roam App is only available in free roam events.
Its primary use is as a hint system to avoid players getting stuck in the free roam.
The app will list all the items available for the current free roam event. Red items are mandatory to complete the free roam. Green are optional. White is the exit/end trigger of the event.
Mandatory items must be completed in order to finish the free roam.
Optional items are, as the name suggests, optional. These may involve collectables.
In Easy mode an exact description will be displayed for the available items.
Normal mode will show a vague/rough description. Clicking on the item will show the easy version.
Hard mode will show ?? for each item (in the relevant color). Clicking the item will show the normal version, again for easy.