The king takes the same way it moves: one square in any direction. In this drill the board shows a white king and a few black pieces. Tap every black piece the king could capture right now, and the next board appears.
Get five boards in a row right to earn a silver star, and ten in a row for gold. A wrong tap shows you the answer and starts your count again. Change the level to add more pieces and more look-alikes.
Tip: the king only ever reaches the squares touching it, and it can only take a piece that nothing is guarding. A piece two squares away is safe, however tempting it looks.