A fabulous app that will only work if you actually move the iPad around physically. Could be a great starter for primary school or lower secondary students.
Extremely useful website (and Android and iPad app) that is real-time flight tracking. Click on any yellow plane to pull up a side menu that gives you flight data (altitude, latitude, longitude, vertical speed, etc.). Click on 3D and it will bring up a cockpit view (you must have Google Earth installled to access this feature).
Simple and very effective site with interactives that test students knowledge of simple, developing and advanced knowledge of physical and political boundaries and entities. Works brilliantly on IWBs. You may need to use photon on iPads due to flash issues with Safari.