Downloading Ketonix 2.0.4 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 program lies within System Tools, more precisely Device Assistants. This free Mac app was originally designed by Ketonix AB. We recommend checking the downloaded files with any free antivirus.
From the developer:
Ketonix is a software application that lets you measure and analyze breath ketone data from a Ketonix Bluetooth or a Ketonix Link device. With this program, you can measure your ketone production by analyzing your breath. It is designed to help you measure how well you’re doing at burning fat.
You may want to check out more software for Mac, such as iStar Composer, SpaceReporter or Matchprint Virtual, which might be similar to Ketonix.