"Behavior to Know the Countries of Kings" is an educational book app developed by So Smart Apps. The app offers a digital version of the book written by Ahmad ibn Ali ibn Abd al-Qadir Abu al-Abbas al-Husayni al-'Ubaidi al-Maqdisi, a historian of the Egyptian lands. The book is a valuable reference for those interested in history and geography.

The app includes several features that enhance the reading experience. Users can customize the font size, color, and style from a selection of eight Arabic fonts. The app also allows users to choose from hundreds of colors and dozens of themes for the page background. Users can even select from a variety of images as their background. The app also offers a night reading mode for comfortable reading in low-light conditions.

The app includes a side menu with all the chapters for easy navigation. Users can also search for specific words within a chapter or across all chapters. The app includes a bookmarking feature to save the last-read page, the last-read chapter, and favorite chapters. "Behavior to Know the Countries of Kings" is a free app available on the Android platform.