Moving files: You have a lot of choices, and they all have drawbacks. Emailing files gets unwieldy when you make a lot of changes, and some people worry about the security of cloud services like Dropbox. You can set up file sharing in System Preferences > Sharing, but it can be a confusing process for beginning users, especially using it cross-platform. iTwin combines the ease of using a USB thumb drive with the seemingly magical convenience of file sharing—the company wants you to think of it “like a transfer cable without the cable,” and that’s pretty much how it works.

You install the iTwin software on your Mac, then insert the two-part dongle into a USB port. The software prompts you for a “friendly name” (which is really only important if you are using more than one iTwin), and an optional password. If you enter your email address, it sends you a disable code, so if one half of the iTwin gets lost you can remotely disable the connection between the two halves.

Then you’ll see a “Local Files” volume, as if you had a USB thumb drive connected. You drag files into that volume, which enables sharing by any other internet-connected computer that has the other half of the iTwin plugged in (and the iTwin software installed). That remote machine can be a PC or a Mac, and the remote files stay perfectly synced.

This is great if you’re on the road with your MacBook Air and you want to grab some files stored on your larger-capacity iMac back at home. Or you want to share photos and videos with your computer-illiterate family without them having to use a browser or FTP client. Or you want to give half the iTwin to a client or colleague and collaborate on documents without worrying about versioning or letting a cloud service get in the middle. It’s painless.

iTwin uses AES-256 encryption, plus the optional password, so your transfers are secure without needing to fiddle with a VPN or login. The ability to remotely disable the connection covers you in case one half of the iTwin gets lost. (Plus, you can just unplug the not-lost half from your machine—both halves need to be plugged in to a running, internet-connected computer to work.) And users can drag the shared files to their local desktop or just open them directly from the iTwin’s “volume,” for ultimate convenience.

The bottom line. It works well, although you’re paying for convenience alone—secure file transfer doesn’t need to cost $99.