After downloading the basic app for tje London underground, I decided to get the professional app for about $10. Turns out my very first "map" was actually a booklet about accomodation in London. Not what I wanted. Oh! And it would have been perfect if I were looking for accomodation in 2009 - not four years later! Rip-off!
uddingstonboy about London Transport Map - Tube Map and Route Planner, v5.1.1