This app is a free, in-browser tool for seeing scales, chords and intervals across the fretboard of many string instruments. So.. does the world really need another fret visualizing tool? Well, probably not. But this one does exactly what I want for myself i.e.

• Focus on intervals
• Easy to share a custom chord, arpeggio or scale by simply copying the url
• Support for different string instruments, tunings and also things like left-handed players
• Hopefully simple UI without sacrificing power
• Ability to save one or multiple fretboards, useful for teaching and/or printouts
• No sign-up, free of cookies

On privacy: holyfret needs no sign-up and sets no cookies. It uses Umami — a privacy-friendly analytics service — to measure traffic.

It's open source — the code lives on GitHub. Requests for improvements or other feedback can be sent to holyfret @ protonmail . com