Review Well, no one saw this one coming. Samsung has succeeded where Microsoft and HP have struggled (so far) in turning a phone into a PC.

When Samsung unveiled the Galaxy S8 last month, its new multimode capability DeX (for "desktop experience") barely got a mention. With a new dock, the DeX Station, the Galaxy could plug into a keyboard, mouse and a larger display, for a desktop-like experience: with apps that rescale smartly to landscape format, overlapping windows and window management. After putting it through its paces, I'm hugely impressed. Samsung has done a solid and thoughtful job here.

This is significant. Giving a phone multimode isn't a new idea, and was pursued for a while by Motorola with Atrix. Atrix was canned five years ago, and for ages nobody picked up the baton, even though phones got ever more powerful, and the software more mature.

For Continuum, Microsoft created a class of portable Windows 10 mobile apps that were desktop friendly (UWP), but it failed to support the existing WP app catalog, which couldn't convert. Microsoft's already weak position in the mobile market deterred app writers from targeting a niche within a niche. And Microsoft has been slow to develop the functionality: here we are, two years on from the first Continuum demo, and it still lacks the promised multiwindow support.

Android doesn't have these problems, because it's already the world's most popular OS, and because it's Java and the apps are portable. A Remix OS PC will run apps from the Google Play store. So Android has great untapped potential to be the leading multimode OS. And with Android Nougat 7.0, Google has built much better multiwindowing capabilities into Android.

A year ago I wrote about Remix OS, an Android variant that could run on x86 PCs as well as ARM, that could turn ARM tablets into a rich multiwindowing desktop-like experience. But as of today, Remix OS is not in a single phone. Not yet, anyway – it's still at the demo stage.

Samsung's Galaxy S8, despite some serious flaws, will sell in the millions, and all you'll need to turn an S8 into a computer – presuming you already have a display, keyboard and mouse – is the £129 DeX dock. You don't need to download any drivers. And unlike Continuum, the experience is far more rewarding.

Despite HP's sterling efforts, Windows 10's Continuum has run smack into a brick wall: the app problem is crippling. As I've noted several times, staples such as Slack and Evernote are UWP apps in the Windows 10 Store but for desktop only, so after you dock your phone they don't open on your main display: the phone versions aren't multimode. It's an absurd situation, and unlikely to be improved until ARM hardware handles Windows 10 much better.

The Dock

To get up and running, all you need is the DeX Dock. This comes with no cables, nor even a power supply: the understanding is you can use the power supply that came with your Galaxy S8, and plug into the dock.

The DeX dock has a clever design. Tip the lid forward to open it, which reveals the USB Type-C port and a speaker built into the lid. It features an HDMI socket, two USB Type A sockets, an Ethernet socket and the USB Type-C socket for the power supply.

But no mic or audio port, which we'll come to. If DeX works for you, you may want to buy another Quick Charge 2.0 power supply, as with the DeX you lose the Galaxy's rapid charging. Because the phone is doing extra work, the rate at which the battery recharges diminishes significantly to a slow crawl.

Docking could be a bit easier – the dock's connector hinges to allow the phone to be used at different angles. The dock doesn't have guides, so you have to guess the trajectory and get it exactly right. And I suspect a Galaxy S8 wearing a decent case won't fit. But after that it's mostly plain sailing.

There's a welcome screen and you'll be asked to confirm whether you want to mirror the phone's display or use it in DeX mode, but then bang, you're good to go.

Setup and driving

The [buzzword alert] "onboarding process" couldn't be simpler. The only wrinkle was the advice in the QuickStart guide to download the DeX app first. But there is no DeX app.

Just plug it in and you're prompted whether you're mirroring (for a presentation) or want to use it in desktop mode.

The desktop is a familiar generic modern desktop, with a taskbar along the bottom, a Start menu floating on its left, and a notifications area down on the right.

The Samsung Dex desktop [click to enlarge]

All windows overlap, but DeX-aware apps scale well and run in a landscape window. Apps that are not DeX-aware run in the portrait mode just as they would on the phone.

Samsung shows you which apps are already DeX-friendly – and this is where there's a nice surprise, because an impressive number already are.

This shouldn't be surprising: app developers who targeted tablets as well as phones have already made their phones multimodal, and DeX is really projecting a tablet design on to a display.

The Start menu operates much like a classic Windows menu since Vista – type in the app name to narrow down what it shows.

DeX gathers the avalanche of Android notifications neatly in the corner:

Notifications will look familiar, too:

Naturally there's an Alt-Tab task switcher. Keyboard shortcuts are very welcome:

Performance is pretty good on the Samsung Galaxy S8+ on loan from EE. I didn't find the phone getting hot driving an external display, but then the Galaxy has far more pixels to drive undocked than it does docked to an ageing 1920x1080 HD monitor. In fact the Galaxy S8 doesn't even default to its built-in display's highest resolution.

It wasn't quite perfect. The browser will default to mobile scaling, so text looks gigantic.

And the absence of a mic port is puzzling. The DeX station booms out decent audio for conference calls, but I don't necessarily want all phone calls piping through the speaker. The DeX station wouldn't recognise a Plantronics USB headset, so that leaves Bluetooth as your only option for privacy here.

But these are minor wrinkles. DeX greatly expands what you can do with a phone. Continuum's app gap means it currently has little appeal beyond Microsoft enterprises. But Samsung already has a strong offering here with Knox, and it knows how to make a phone. I found the Galaxy S8 experience significantly marred by a single poor design decision (the sensor) and Bixby, both of which made the device unnecessarily annoying to use. But given the pace of progress, millions, and soon billions, of phones will be able to run a DeX-like experience.

Developers can find out more about tweaking for the desktop here.