Рыцарь Пустыни is an Android app developed by belbox. It is a free educational reference book that offers insights into Muslim military history. The book is dedicated to one of the most prominent warriors in the world, Khalid ibn al-Walid, who was born in the city of Mecca, in the Quraysh tribe. Initially, he was an opponent of the Prophet Muhammad, and in 625, he inflicted damage to the Muslims in the battle of Uhud. Later, he converted to Islam and became an important military leader of the prophet, receiving the nickname of "The Sword of Allah."

The book provides a detailed account of the life and military campaigns of Khalid ibn al-Walid, who was a conquering hero and never knew what military defeat was. It is an excellent resource for those interested in history, particularly Muslim military history. The book is well-written and provides an accessible and engaging account of one of the most prominent figures in Muslim history. Overall, Рыцарь Пустыни is a must-read for anyone interested in Muslim military history.