...
1Build the shape
Click one fret per string, exactly as you would hold it. Picking a second fret on a string moves the note.
2Read the name
Umaro reads the lowest note as the bass, so inversions and slash chords are named correctly.
3Hear it back
Tap the result to strum the shape, and check the alternatives for a simpler spelling.
How to name a chord from its notes
Chord naming is a lookup in reverse. A shape on the fretboard is just a set of pitches; naming it means finding the root those pitches stack thirds above, then describing what was added, altered or left out.
Click the frets you are holding, one per string, and Umaro does that work. It reads your lowest selected note as the bass, so an inversion is named as an inversion — C–E–G with E underneath comes back as C/E, not as a rootless E chord. Where a set of notes has more than one honest reading, the alternatives appear beneath the result: A–C–E–G is both Am7 and C6, and which one is right depends on the key you are in, not on the shape.
From here, browse every guitar chord, compare voicings in the chord library, see the chords in a key, or go the other way and find a scale from notes.