Lagu Wajib Nasional + Not Balok is an Android application developed by Annisa Cipta Informatika that focuses on providing a comprehensive offline collection of 30 Indonesian patriotic songs. The app is designed to help users learn and memorize the lyrics, sheet music, and numerical notations of the songs, making it a great tool for both students and enthusiasts.

The app offers a variety of features, including a complete offline mode that eliminates the need for internet connectivity. The app's compact size also makes it an excellent alternative to similar apps that require more storage space. Overall, Lagu Wajib Nasional + Not Balok provides a user-friendly and accessible platform for learning patriotic songs.