Kitab Sirr Al Asror is a free Islamic book app developed by Az Zikr Studio for Android devices. The app contains the Sufistic book by Sheikh Abdul Qadir al-Jailani that is known for its 24 secrets in organizing hearts to the peak of Makrifatullah. The book reveals the secrets of all secrets of life and contains 24 kinds of secrets that guide the reader towards the path of Allah.

The content of this application includes an extract of the letter of Sheikh Abdul Qadir al-Jailani, an introduction, and 24 chapters that cover human spirituality, repentance, self-purification, Islamic spirituality, and Sufi experts. The app is very light, easy to use, and can be run with or without an internet connection.

Overall, Kitab Sirr Al Asror is a simple yet informative application that provides valuable insights into Islamic spirituality and Sufism.