Kendama: Your Dexterity, Skill - App Store

The kendama (けん玉, "sword [and] ball") is a traditional Japanese skill toy. It consists of a handle (ken), a pair of cups (sarado), and a ball (tama) that are all connected together by a string. On one end of the ken is a cup, while the other end of ken is narrowed down, forming a spike (kensaki) that fits into the hole (ana) of the tama. The kendama is the Japanese version of the classic cup-and-ball game, and is also a variant of the French cup-and-ball game bilboquet. Kendama can be held in different grips, and the tricks and combinations that can be done are limitless. The principle of these toys is the same: catching one object with another, where both are joined by a string.

The origins of kendama are disputed, but it is generally believed to have originated during the 17th or 18th century. Kendama started to evolutionize when it came to Japan during the Edo period, and since then the use of the toy has spread throughout the world. The size and materials used to create kendamas now vary as they are offered in jumbo and mini sizes, and have been created out plastic, metal, and nylon. There are now kendama competitions held in countries all over the world, the biggest competition being the annual Kendama World Cup in Japan. [from Vikipedia]