Short answers to what people ask first.

Does it need the internet?

No. Your iPhone sends photos straight to your Mac over your home Wi-Fi, so syncing works without an internet connection. You only need the internet to start the trial, buy the unlock or restore a purchase through the Mac App Store.

Does it work without a Mac?

No. The iPhone app sends photos to Shelfroll Hub on a Mac, which writes them to your drive. Without the Hub the iPhone app has nowhere to send them.

What happens if the trial ends?

Nothing on your drive is touched. Shelfroll stops copying new photos and tells you so, and everything already backed up stays where it is. Unlock it once and it carries on.

Can I use the drive on Windows?

Yes. The drive is formatted as exFAT, which Windows opens natively, and your photos are ordinary files in ordinary folders.

Who sees my photos?

Only you. Photos go from your iPhone to your Mac over your own network, through an encrypted connection, and are stored only on your drive. Nothing is sent to the developer or to any other server. See the privacy policy.

Something else? See Support.