Крепость мусульманина is an Android application developed by IslamBooks that falls under the Education & Reference category. The app is free to download and use. The program name translates to "Fortress of the Muslim" and it is based on the words of remembrance of Allah found in the Quran and Sunnah.

The app features a user-friendly interface that allows easy navigation to different sections. It includes a wide range of Islamic prayers and supplications that can be used in daily life situations such as waking up, eating, traveling, and more. The app also offers audio recitations of the prayers in Arabic, along with English translations. Overall, Крепость мусульманина is a useful tool for Muslims who want to incorporate more remembrance of Allah into their daily routine.