Buku PJOK Kelas 7 Kurikulum 2013 is an Android application developed by Pustaka Biru. It is a free education and reference app that provides an electronic book for Physical Education for 7th-grade students. The app includes a comprehensive guide for the subjects of Pendidikan Jasmani Olahraga dan Kesehatan (PJOK), which means Physical Education, Sports, and Health. It aims to encourage physical growth, motor skills development, knowledge acquisition, and critical thinking skills. The app covers various topics such as ball games, athletics, martial arts, gymnastics, rhythmic movements, and swimming, among others. It also discusses healthy eating habits, proper nutrition, and the development of teenagers' bodies. Overall, the app is a useful tool for students who want to learn PJOK at their own pace and convenience.