Reference note from an iPhone

What is the quickest way to get a reference note from an iPhone? Does any app offer a quick access widget? Opening Garageband or similar takes a week when you just quickly want to check a note.

Blowing a random note on a Hohner Super Chromonica every now and then just gets unnecessary attention :slight_smile:

Download any free synth or keyboard emulator app with a keyboard. Choose your reference pitch. Go forth in sin.