It gives you info like this stuff here.
There's pitch analysis as well as waveforms which can be great to show your students to highlight syllable stress, rhythm and pitch.
So instead of drawing your impression on the board you can show them their voice in these visual forms. If you then do your YOURS, the differences become obvious and measurable quite a bit faster.
The download is free and is worth it if only to support the co-developer Paul Boersma in getting some press and eventually some hair gel.
Download as soon as you can. And bring that computer to class.