When you first run this app, it allows you to enter your credentials to The Routing Project. Subsequently, you only have to tap the icon to open a map in a browser and see the location of those with the same Org ID as you. To change your credentials (to re-enter them), go to TRP On Ramp's "App info" screen (Settings > Apps > find TRP On Ramp in the list of Downloaded apps and select it), tap the "Clear data" button, then run TRP On Ramp again.