오누이 is a free iPhone app developed by Onuii Inc. It falls under the Education & Reference category and offers a wide range of features for students. With 오누이, students can ask questions about various subjects including math, English, science, social studies, and Korean. The app allows users to connect with experienced tutors who are available to answer their questions in real-time, eliminating the need for waiting. In addition to subject-specific tutoring, 오누이 also provides mentoring and guidance on studying, college entrance exams, and career choices.

Overall, 오누이 is a comprehensive app that aims to support students in their academic journey. With its easy-to-use interface and access to a large pool of skilled tutors, students can expect to receive timely assistance and improve their grades. Please note that this app is exclusively for student members, and tutors should use the separate 오누이튜터 app.