One of the chess tactics, it is an app that summarizes the opening book of the right Shiken rook.

Right Shiken rook is a kind of rook tactics residence, has been called from the fact that it put the rook to the fourth column from the right (right Shiken) and right Shiken rook.
The attack by the concentration of the flight angle Lady Amherst's pheasant handed to 4 muscle, it is a highly offensive power tactics.
A long history as a tactic, Senkei of the oldest is a game record Ohashi SoKei pair Honinbo calculated sand against the existing (1607) has become a Shiken rook versus right Shiken rook.

Books following we were allowed to reference for each procedure.
Kanai HisashiFutoshi five-stage al., "Versus multicolorfin rainbowfish Yagura victory Guide"
Fujii Takeshi Kudan al., "Key points of Shiken rook"

This application is possible to use even offline.