Mac OS users do not have to use a tool to format a USB device as they can simply format their drive through the Mac OS.
Please follow the steps below on how to format the Clickfree on Mac:
1. Plug the Clickfree into your Mac and make sure that your Mac is reading your USB.
2. Open Disk Utility. To do this you can press Command and Space Bar then search for Disk Utility.
3. Once the Disk Utility window is open, you will brought to the menu below, and as you can see the External USB is showing on the left pane. Choose the drive you’d like to format.
4. Click Erase to access the disk-formatting settings.
5. Choose MS-DOS (FAT32) from the format drop-down list.
5. Click Erase to format.
6. Right-click the drive on the desktop and choose ‘Get Info’ to confirm the FAT32 change.
You may safely remove the Clickfree USB from your Mac.