Unfortunately you can't necessarily drag and drop columns around in this version of gantter to change the order but you can disable and enable columns using the "View" menu toward the top left hand corner of your screen. That way you only see the columns you need that are relevant to your project, this suggestion for a feature in a future release of gantter has been made before though and it is on our roadmap to include in a future release. Let me know if you need additional assistance or have further questions.

Kind Regards, Sophia