Download of Cleanboard 2.0.3 for Mac was on the developer's website when we last checked. We cannot confirm if there is a free download of this app available.
According to the results of the Google Safe Browsing check, the developer's site is safe. Despite this, we recommend checking the downloaded files with any free antivirus software. This free software for Mac OS X is an intellectual property of Mr. Proton Studio. The software lies within System Tools, more precisely System Optimization.
From the developer:
Cleanboard is an application that helps you keep your clipboard clean. When you copy a file, it is saved to the clipboard on your Mac. Yet, your clipboard is using a lot of memory. In addition, anyone can access the files or information from your Mac. With Cleanboard for Mac, you can clean your Clipboard, delete passwords, images, text, files, copies, URL, or anything you have copied on your clipboard.
You may want to check out more Mac applications, such as Jitouch, AntiRSI or PresButan, which might be similar to Cleanboard.