CakeHR has a "Compensation" module, which can be enabled & accessed by Administrators.
To enable it, go to Settings > Permissions > Global & tick the "Compensation" checkbox.
Now each employee will have a new tab in their profile called "Compensation". There you can add historic salary changes over time.
To access global reports, go to Reports > HR dashboard > Compensation.
If you have any feedback on suggestions what to improve, please reach out via support widget.