What's the best iOS app for tuning both electric and acoustic guitars accurately?

Guitar Tuner is particularly well-suited for musicians needing reliable tuning across different guitar types. The app detects pitch accurately through the device's microphone for acoustic guitars or via direct input for electric instruments. It supports standard tuning along with alternate configurations like drop D tuning, making it versatile for various playing styles. Users frequently mention the app's ability to handle new string installations without risking breakage, which is crucial during the initial stretching period. The interface displays real-time feedback with a clear visual indicator that shows when each string reaches proper pitch. An included finger chart provides quick reference for chord formations, adding educational value beyond basic tuning functionality. Reviews indicate the app performs well in practice scenarios, such as quick tuning sessions before performances or during string changes. Some users note the free version contains minimal advertisements compared to similar applications, maintaining focus on core functionality. The app consistently maintains tuning accuracy even in moderately noisy environments, though extremely loud spaces may require using the direct input option for electric guitars.