The 가톨릭Catholic 기도서 is an Android application developed by hk.ha that provides a collection of daily Mass and various Catholic prayers. The app includes the music sheet for various Catholic hymns and also features a search function for hymn numbers and contents. The app offers the ability to zoom in and out with multi-touch gestures and provides the music sheet in a printable format. The app is available for free and can be used even without an internet connection.

The app is designed to help users in their prayer life and offers a comprehensive collection of Catholic prayers. The app has a simple and intuitive interface that is easy to navigate. The inclusion of music sheets for Catholic hymns is a useful feature for users who want to learn and practice the songs. The app's offline functionality makes it convenient to use, especially for users who do not have consistent internet access.