Think 1.0 by Freeverse is a pretty cool idea. It's a free application that puts a simple solid background behind the app you want to focus on. This is a great way to get rid of distractions while working on something important.
The user interface is a little weird, though. The main function- putting focus on an application, should be simple and easy to do. And to a certain extent, it is. When you launch Think, you're greeted with a panel (the "Illumination panel") that makes you choose which app you want to focus on. Once you've found and clicked this app in the panel, Think starts to do its job, and also puts the icon of the application in the "Think" bubble. Simple, right?
There are actually a few problems with this user interface. First, chances are my active application is already the one I want to focus on, so I shouldn't need to choose it again. Second, the behavior of Think's dock icon is confusing. I don't know how many times I've clicked the Think icon to try and activate Safari, only to have the "Illumination panel" reappear so that I need to choose the app again. This is especially confusing when the Safari icon is in the Think bubble.
Even worse, the "control panel" appears to have limited value. Do I really want to change the color and opacity? What's the difference between quitting Think and disabling it?
So why not have something like
Time Machine? You'd activate the application in Mac OS X (if it's not already active), click the Think icon in the dock, and have the background applied right there with no interruptions. Once you're done, you'd simply click the Think icon again and the background would fade away. This would be a much better interface.
It sounds like I am being picky, but a user interface is one of the most important parts of an application. For an application that promotes less distractions, it should not be confusing to use. It's still a great idea, so I'd love to see it eventually changed. With the way it is now though, I won't be using it anytime soon.