Click the cog wheel icon: above the fretboard to open the settings menu.
Click the pen and paper icon:above the fretboard to open the style menu.
Click the string name letters behind the guitar nut to open a drop down menu to custom tune each string individually.
First displayed chord is the chord with the lowest note displayed considered as the root. Each subsequent chord(s) are what the chord would be if the lowest note was not the root.
Second column of chords as called slash chords. It denotes that the chord is the written chord, but with the note after the slash is currently being played as the lowest/bass note.
Chord Analyzer uses an algorithm to try and determine the name of the chord for the given notes. Based on function and convention, some chords may have alternate names not displayed here. If you feel any chords are egregiously wrong, feel free to contact me.