1) Tap on the Cloud tab in the app.
2) To the right of each Folder, you should see three dots. Tap this.
3) Tap on "Delete Folder".
4) You will be prompted to type "DELETE". Type this correctly to confirm this deletion.
Note: Deleting folders will also delete any Projects within them so ensure these are either moved to another Folder or no longer required before deleting any Folder. This cannot be reversed.