iXpand Sync shows the contents of your drive, and a big + button lets you access the photos and videos stored on your device, so you can transfer them to the flash drive. You're able to create whatever kind of folder structure you want for your iXpand. If you don't want to add your photos manually, the Camera Sync option in the sidebar will let you set up an automatic sync of your Camera Roll whenever you connect the drive.
You can tap on any file in iXpand Sync's lists to view it, or swipe it to the left and tap a button that looks like three vertical dots for more options, including opening it with another app, sharing over AirDrop, moving it to another folder on your iXpand, or locking it with a password and 128-bit encryption. Those extra options could be a little easier to find — I'd love to see the same three-dots button added to the screen where you view the file too. They're present when you're looking at image files, but not on other filetypes, like PDFs and spreadsheets.
The app lets you delete files stored on your drive, but not files stored on the phone itself. Once you've copied photos from your Camera Roll to the iXpand, you still have to pop over to the Photos app to delete them there in order to free up space on your iPhone or iPad. That's for the best, though — I don't know of any third-party apps that let you delete photos from your iPhone, and if iXpand Sync could do it, it would be easy to get confused as to whether you're deleting apps from the drive or from your actual iPhone.
One of my favorite features is being able to load up the iXpand with movies from my Mac's hard drive, without having to convert them to formats that the iPhone and iPad can play natively. Supported formats include WMV, AVI, MKV, MP4, and MOV. Then when you connect the iXpand to your iPad or iPhone, you can watch the videos inside the iXpand Sync app, which transcodes them behind the scenes.
You can even transfer files from the iXpand drive to your phone. They stay within the My Downloads folder in the iXpand Sync app, but from there you can open and edit them in other apps, share them, send them to cloud storage, whatever. While the iXpand excels as a way to add to your device's built-in storage, it's also nice to be able to pull a file off the iXpand so you can work with it on your device without having to keep the iXpand tethered to your Lightning port.
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