Oud Tuner is a free iPhone app designed by Hsing-Fu Hsueh, falling under the Multimedia category with a focus on Music & Radio. The app offers a simple user interface with noise filtering to assist users in tuning strings effortlessly. By selecting the frequency and tuning on the screen, users can easily see the pitch of the individual string as they adjust it.

The app features a variety of functions including sound calibration, reference sound options, one-key tuning mode, and precise tuning scales. With a visual indicator showing pitch accuracy and lighting cues for adjustments, users can fine-tune their Oud strings effectively. Oud Tuner also provides 15 tuning modes for Arabic and Turkish Oud, along with a built-in metronome with intuitive beat mode selection and support for different beat subdivisions.