Displaperture is a simple utility designed for Mac that puts rounded corners back on your screens and changes the appearance of your display. This program was developed for those users who are nostalgic over the CRT monitors that used to provide you with round corners on their displays.
The application is very simple to handle, works on multiple monitors, and uses a small amount of CPU resources while it's operating. A good thing about this program is that it offers an option to adjust the corner radius level according to your requirements.
The program lets you choose which screen corners you want displayed as rounded. Furthermore, if you work on multiple screens, the application can apply the round effect on all screens or only on the display that has the Menu Bar.
Personally, I wouldn't keep this application on my Mac as I'm happy with the way my display looks (sharpen corners). Nevertheless, I imagine graphic designers or CRT nostalgics would appreciate this utility's features.
As a conclusion, this program might prove to be of good use only to Mac users who prefer the corners of their screen rounded. If you're not one of them, I'd say it's not worth installing this application on your Mac.