Богородице Дево радуйся is a free Android app designed for Russian Orthodox Christians. The app contains the most famous images of the Mother of God, with descriptions, prayer texts, and a brief history of the icons. It also includes the "Rule of the Theotokos," which covers the entire life of the Mother of God, divided into 15 decades according to the most important events in Her life. The app includes the Psalter of the Most Holy Theotokos (audio) and several Orthodox radio stations. When the smartphone is turned horizontally, only the image of the Mother of God and the prayer text to this icon remain on the screen. The app currently contains 30 images of the Mother of God, with their names and photos. The app also includes the "Rule of the Theotokos" song performed by the Optina Pustyn Brotherhood choir. However, internet connection is required to listen to the song and the radio stations.