Downloading cb2bib 2.0 for Mac from the developer's website was possible when we last checked. We cannot confirm if there is a free download of this app available. The software lies within Productivity Tools, more precisely Office Tools. This free Mac application was originally created by molspaces. We recommend checking the downloaded files with any free antivirus.
From the developer:
The cb2Bib is a free, open source, and multiplatform application for rapidly extracting unformatted, or unstandardized bibliographic references from email alerts, journal Web pages, and PDF files.
The cb2Bib facilitates the capture of single references from unformatted and non standard sources. Output references are written in BibTeX. Article files can be easily linked and renamed by dragging them onto the cb2Bib window.
You may want to check out more software for Mac, such as PitStop Extreme, 3dissue or FileOpenInstaller, which might be similar to cb2bib.