In terms of direct integration, you won’t find a better solution than Clockify. I researched more than 60 options before settlng on Clockify and suggesting to the Infinity team that they add it as an option.
If you are initiating the timer from within the project, it is very easy to match up the project within the timer to the project in Infinity. In fact, Clockify is one of, if not, the best tool for this scenario.
If you are trying to achieve an automation (e.g. create a project in Clockify automatically when it is created in Infinity or vice versa) I don’t think you will find anything that does that natively. Perhaps it could be done with Zapier? I haven’t tried that but maybe I’ll give it a go.
When/if Infinity supports webhooks or opens their API the opportunities will likely open up. @Jovana
In the meantime, if you’d like help leveraging Clockify I’d be happy to help.