Fretful is a fretboard tool.

Fretful generates musical scale information and charts it onto a fretboard. The fretboard can display up to 12 strings, and all strings are chromatically tunable. 9 of the strings are playable with sound. The sound abilities are only meant as a toy, and in this web version they are less than likely to be stable, but can still be useful for quickly getting an idea of how different scales or tunings sound. There is an Android version available by the same name on the Play store. 

Fretful is designed to remember the key root and scale you set it to and automatically set it to the last used settings every time you open it. It saves a few other settings the same way: all of the setting from "Basic Fretboard Display Settings"; the number of strings displayed; and the tuning of the strings. It also has several savable options. This web version should work with all of these settings if used in a browser that allows it, but if you clear you browser history you're likely to clear any Fretful save information.

This is a tool for experienced musicians. What is does is obvious just by looking at it, but specific detail is available in a built in help menu.

You'll probably notice the blank space where the screenshots have a "Play on Touch" menu. The audio was too unstable for this web browser version so I removed it. I forgot to remove the pages about sound related features from the help menu. You can safely ignore that.

Also available on