A metronome, a tuner and a drone. They work in this browser: the tuner listens through your microphone, and nothing it hears is sent or kept.
Free for anyone to use, with no account. Teachers can ask pupils to log their practice in a class on The Skill Site: see The Skill Site for music teachers.
80 beats a minute
Start the tuner, then play or sing a note.
It listens through your microphone. Nothing it hears leaves this page.
A held note to tune scales and long notes against.