Pick a progression, a key and an area of the neck. Press play and the chord tones light up in time with the changes, so you can hear each chord and see where its notes are while you play.
Tap a chord to see its tones.
Pick a five-fret area and keep your hand there. The point is to find the next chord's notes without jumping around the neck.
The dots switch to the next chord half a beat before it arrives, so you can see where you're going in time to get there. Make it a full beat early if you need more warning.
Once a progression feels familiar, switch the dots to On the change, then try it with your eyes closed. The dots are there to get you started.