Starting from version 2.0, FenixTrek PRO is free.
No activation required, all PRO features are enabled.
https://apps.garmin.com/apps/1260406a-c947-4de0-bd91-f6924e142980
Hosting for website and Theme Designer is down, so editor for custom color themes will be unavailable online.
However, Theme Designer can work locally in a browser and you can download it from github:
https://github.com/pzagawa/FenixTrek-Theme-Designer
Thank you all who supported my work.