Unfortunately, it seems broken (on FF 60.7esr at least), reports the same fingerprint signature on https://browserleaks.com/canvas every time. It might still be useful to detect fingerprinting attempts by websites.
Furthermore, even though it is marketed as open-source software, the authors don't link to any repository of their code, so I was unable to see what it does.

I could NOT stop the popup from popping up telling me it was doing it's thing! And it covers vital needed parts of tabs so I was constantly clicking the fool thing and I sometimes clicked a tad off and closed my entire browser and lost all my tabs etc. So a minute ago I had had enough and removed it .

Canvas Fingerprint Defender has a bug on chrome, i tested it also on firefox has this bug.
Canvas Fingerprint Defender will cause website auto jump failure.
you can reproduce in this link:
http://codersclub.org/discuzx/member.php?mod=register
no matter login or register, page does not auto jump.
Maybe make a option to keep a same Canvas Fingerprint for a while like 5 minutes would solve it.