Acoustic Tuner is a versatile guitar tuning app available for iPhone. It offers both automatic and manual tuning options, making it a convenient tool for guitarists of all skill levels.

With the automatic tuning feature, Acoustic Tuner utilizes the iPhone's microphone to detect the pitch of each string and provides real-time feedback on whether the string is in tune or needs adjustment. This makes it easy for beginners to quickly tune their guitar accurately.

For more experienced guitarists who prefer manual tuning, Acoustic Tuner also offers reference sounds. By playing the reference sound for each string, users can tune their guitar by ear, ensuring precise tuning based on their personal preference.

Overall, Acoustic Tuner is a user-friendly and practical tool for guitarists. Whether you prefer automatic tuning or manual tuning by ear, this app has you covered. And the best part? It's completely free to download and use!