A free app for Android, by Henry Hoff.

Ninjutsu is a Japanese martial art that was developed during the period of the Japanese Renaissance. It was used as a tool to learn the secret methods of combat and to enhance the abilities of the shinobi or ninja.

It is a brutal fighting style, but also a very efficient one. Ninjutsu can be defined as a mixture of karate, kung fu, and wrestling, with a strong emphasis on mental discipline and control.

The ninjutsu system is based on a series of techniques that are used to defeat an opponent. Each technique is divided into several steps, and each step is defined by a specific movement.