Tangram for Osmo, is based on an ancient geometric puzzle using seven wooden pieces, all with different shapes and colours. The app works with the Osmo product. It displays the outlines of a puzzle you must recreate using the pieces. At the easier levels, as you place one correctly, the app fills in the puzzle onscreen with the appropriate colour. If you get stuck, you can ask Tangram for a hint. There are more the 2,400 puzzle combinations. So plenty to keep children (and adults!) entertained for hours.