A free program for Android, by Subway Maps by LithoByte Co..

Stockholm Metro is the navigation app that makes getting around the city by subway or train easier than ever. No need to pay for a ticket or to buy a pass. You can just open the app and start using it. You don't even need to have any previous knowledge of how the system works.

Just tap on the map to get the most up-to-date information on where the nearest subway or train station is, and you can easily see the routes that go where you want to go. You can also see the next and previous station, so you can easily change trains or get off at the station you want to visit.