"The Mystery of Hizen Nagoya Castle" over the Hizen Nagoya Castle Ruins while the riddle, and it is the Saga Prefectural Nagoya Castle Museum Nagoya Castle Ruins official guide app.
Xeen is the developer of the app which can be found in the Entertainment category. Hizen-Nagoya Castle has been downloaded and installed by over 1K users and its most recent update was released on Mar 14, 2017. Google Play shows that this application is rated 4.4 by its users.
You can get the setup package of Hizen-Nagoya Castle 2.2 for free and take a look at users' reviews on Droid Informer. The app runs on Android 4.0.3 and above. It's secure to download the app.