The 4.0 version of ClassLinkExtension for Mac was available to download on the developer's website when we last checked. We cannot confirm if there is a free download of this app available. We recommend checking the downloaded files with any free antivirus. The program lies within Internet & Network Tools, more precisely Browser extensions. This free Mac application was originally created by ClassLink, Inc.
From the developer:
ClassLink LaunchPad Extension gives students and teachers one-click access to their web apps and files. ClassLink empowers students and teachers with instant access to their learning resources. It includes a library of over 6,000 single sign-on apps and instant links to file folders at school and on Google, Office 365, and Dropbox cloud drives.
You may want to check out more Mac applications, such as Bwana, G-Force Toolbar or Safari Cookies, which might be similar to ClassLinkExtension.