I use the latest Mac hardware and software, and used the current version of this product, which says it works with what I have...

Two things:

1. This app is extremely annoying, as it makes certain documents in the background largely transparent, and if you have more than one document in the background (the usual situation), they bleed through, making everything visually garbled.

There are many times you want to glance over at a different document or window you have open, in order to work in the one you're in. For example, you're on a web page in Safari and you want to glance at another page you left open, with info on it, or maybe glance over at a mail document you're referencing. Or a Text Edit document. If there is anything behind it--even a desktop picture that isn't a plain solid light color--you'll be unable to read it. Everything bleeds together into a mishmash of translucency.

You can't even easily and quickly click on the other window, since you have no way of knowing, visually, which window or document is on top (of the pile below the window you're in). It will look like you're clicking on the window you want, but no, you're clicking on one layered above or below it, which then pops up opaque and you still don't have the window you're trying to read.

2. But it's worse than just annoying. Sometimes this app makes it's impossible to read something, no matter what you do. You know those little little "pop-out" windows that cleverly pop out of certain windows in OS X? An example is when you are selecting a screen saver and there's an Options button. Click it and the little pop-out window slides out and down in front of the window you're in. It has the preferences for that screensaver on it. Tweak how you want that screensaver to behave and then click Okay. The window disappears back into a slot in the main window and you're set to go. Problem is, with this app installed, the pop-out window and it's main window become translucent, blending the text and graphics together, such that you can not read the words and checkboxes. It's all run together. If you're lucky, you'll be able vaguely to see the Okay box for the options and click on it, to get the little popout to go back. You've been unable to set your options but you can at least sigh that you got your computer back from the Twilight Zone.

That style of pop-out most often appears in Mail, when downloading an attached file. I didn't test to see if that works the same as described above.

I have to believe the others reviewing this app just didn't see what I'm seeing, because this is a matter of functionality, not taste.

The developer's download window contains a hugely prominent disclaimer in red letters. That should be a clue.