天國之歌（Songs of The Kingdom）is an educational and reference app developed by 台灣國際基督教會. This app serves as an electronic songbook, providing users with access to a wide range of hymns and songs.

With this app, users can easily search for songs by using keywords. It also offers a convenient feature to create personalized song playlists, allowing users to easily edit the order of songs and share the playlists with others using various built-in apps such as Email, Line, WeChat, and WhatsApp.

Each song in the app comes with lyrics, editing options, sheet music, videos, and music playback (some songs may be restricted due to copyright limitations). The app supports multiple languages, including Traditional Chinese, Simplified Chinese, Cantonese, and English. Some songs even include Taiwanese lyrics, which can be switched using the language key.

Additionally, the app automatically adjusts the default language of the lyrics based on the user's device settings. It provides users with the option to modify the lyrics and offers features such as zooming in on the font size and adjusting the size of sheet music images through finger swiping.

Overall, 天國之歌（Songs of The Kingdom）is a comprehensive electronic songbook that caters to the needs of individuals and groups involved in worship and musical activities. It offers a user-friendly interface and a wide range of features to enhance the singing experience.