Our application contains besides the Psalms of David and the Psalms of the Mother of God divided into 20 Catechisms. The Psalms is an Old Testament book that contains hymns and poems traditionally attributed to the prophet and King David, the ancestor of the Lord Jesus Christ. Virtually every aspect of prayer to God (or God's service) —praise, thanksgiving, repentance, intercession — is covered in the Psalms. The book contains the Psalms of David (150 Psalms / NECANONIC Psalm 151) and is one of the most widely used books of the Old Testament in Christian worship.