Microsoft's Xbox One has supported running UWP (Universal Windows Platform) apps for quite some time now and many developers have updated their apps to allow installing them on the console. It's worth mentioning that it's not enough to just make the app available to download. For a decent experience on Xbox One, developers are expected to optimize it for Xbox One. As we know, the developer behind the official Dropbox client for Windows 10 is Rudy Huyn, who's known for paying a lot of attention to detail. So the official Dropbox app for Xbox One looks great.
The said update is also introducing some new features to the client on all Windows 10 devices. With it now being available on Xbox One, the client's UI is capable of adapting to larger screens. You're also now able to import any content from external USB devices into the Dropbox cloud. It's possible to stream your media content from the cloud to other devices too, without the need to download it first.
Dropbox for Windows 10 devices, including Xbox One, is available to download from the Windows Store for free. And if you were running the official client on your device before, you're probably already running the latest version.