Who can use the CO2 fit app? Changers Support December 15, 2016 09:44 Updated Follow All those who own a smartphone with Android or Apple iOS operating system. For employees in companies we have a webservice. Related articles How to delete my account? How do the employees register in the app? I would like to introduce the app in our company. What should I do? What does the Changers CO2 fit app cost? Where can I get the Changers CO2 fit app? Comments 0 comments Please sign in to leave a comment.