One more to consider is the Strum Acoustic Synth. It shows a nice big representation of the current chord. When you hit stop, it erases the last chord though, which is too bad.
This isn't as nice as the tool you point out that will show you the progression, but it's pretty handy imho. I sometimes use it when doing jams with friends so they can just see what I'm playing... or when changing the key of a project it can be kinda helpful.