Guitar Tunio - Guitar Tuner is a fast, accurate and easy-to-use app offering pro level of tuning precision! The app features different tuning modes, a list of standard and alternative guitar and ukulele tunings, complete with extra tools for beginners and pros. It’s totally free! Guitar Tuner helps you tune your electric or acoustic guitar with a high level of precision and incredible ease. You don’t need any additional equipment - it works with the mic of your device, you don’t even need your guitar amp - it will pick up your electric guitar or bass unplugged.