Boss’ free tuner app looks just like the TU-3, but don’t throw away your pedal yet .
Made by Fender
Fender’s free app sports a clean, modern design and lots of alternate tunings, but the tuner’s essential feature — its tuning meter display — is slow, jumpy and often frustrating to use.
Made by Yousician
GuitarTuna is the tuner offering from the Finnish music education company, Yousician.
Made by Boss
Less of a functional tuner than a descent into a skeuomorphic steampunk nightmare. Martin customers — presumably serious guitarists — deserve better than this.
Made by Peterson Tuners
Peterson’s iStrobosoft app is an impressive piece of engineering, offering outstanding accuracy, detection range and calibration options — all in an intuitive and simple-to-use interface.
Made by PitchLab Smartphone Apps
PitchLab is a very good app for iOS and Android, with a easy-to-use strobe feature.