Sling TV, a new over-the-top streaming service from DISH Network (NASDAQ:DISH), offers consumers a small package of cable channels in a purely digital format with no cable subscription required.

The service, which is still available by invitation only, offers 12 channels -- many of them owned by Walt Disney (NYSE:DIS) -- for $20 a month. The basic package offers access to ESPN, ESPN2, TNT, TBS, Food Network, HGTV, Travel Channel, Cartoon Network, Disney Channel, ABC Family, and CNN on consumers' computers, tablets, phones, and through a variety of set-top boxes. Sling also offers a kids' package with Disney Junior, Disney XD, Boomerang, Baby TV, and Duck TV for an extra $5 a month, as well as a news and information package with HLN, Cooking Channel, DIY, and Bloomberg TV for the same additional fee.

This is the first such package to be offered legally in a purely digital fashion without a cable subscription. Sling is potentially disruptive to the cable industry. It offers cheap access to some programming that formerly could only be viewed in non-TV formats if you also paid for traditional cable.

To be truly disruptive, however, Sling must not only offer these channels, but deliver them in an appealing, glitch-free, easy-to-use fashion.

Sling currently supports Roku's boxes and stick, Android devices, Apple iOS devices (iPhones, iPads, and iPod Touch), Apple Macs, and Windows-based computers. Apps for Microsoft's Xbox One,'s Fire TV and Fire TV Stick, and Google's Chromecast are coming, as are apps for a variety of smart TVs. 

I tested the service during its pre-launch/invitation-only period using an account provided by DISH. For my test, I installed the service on a PC running Windows 8.1, and on an iPhone 6.

Getting started
Installing the app was simple on both devices. Actually finding the Windows version required a bit of searching as it is not on the Sling home page, but that can be explained by the product being in a pre-launch stage. The iOS app required nothing more than a simple search.

I was not able to log in with a temporary password sent by Sling. But the log-in page had a password reset button that sent me an email through which I was able to change my password and enter Sling, which I first did on my PC. (For reference, my office has Comcast business service, and I am able to stream movies crisply to my PC with a wired connection while at least two other people are doing the same. My phone service, using Sprint, has a midlevel strength signal from the same location). 

The app launched immediately into live television -- ESPN in this case -- and the first thing I noticed is the picture started out quite fuzzy -- like an old-time UHF station with lousy reception. That was corrected pretty quickly, settling into an acceptable, if not great, image that was a tad inferior to the same show on cable. The fuzziness returned periodically, but the channels never stalled or stopped to buffer. 

The experience was similar on my iPhone and the picture was no better.

The Sling Interface is easy to use, but picture quality can be less than ideal. Source: Screenshot.

Using Sling
Where Sling has truly succeeded is in building an intuitive, easy-to-use interface. The main screen lists the available channels on a scrolling belt that can be opened or closed by clicking on the picture. Switching between channels is as simple as clicking on a logo and then the "watch" button.

There is also alternate navigation menu on the upper left-hand side of the screen and a second set on the upper right that lets you look at subsets of channels, including sports, entertainment, news, and family. Programming can be paused, reversed in 10-second intervals, and fast-forwarded 30 seconds at a time. 

The Sling app is easy to use, and it's hard to imagine anyone -- especially the millennials DISH is targeting -- having trouble with the feature.

Is it a cable killer?
Sling's main limitation, aside from mediocre picture quality, is its channel lineup -- something DISH spokesman John Tagle told me at the Consumer Electronics Show was a work in progress. As it stands, Sling offers a decent array of channels likely to be popular with its target audience, making the idea of dropping cable more palatable.

On its own, Sling might not be a cable killer, but pair it with Hulu for network shows and Netflix for original programming and movies, and you have a package that rivals cable at a combined cost of under $40 a month. Yes, you'll miss out on some programming -- non-ESPN live sports for example -- but you'll have a wide array of content to watch.

Sling offers just enough live TV at a cheap price to make it attractive for cord cutters. It's not a cable killer, but it's another nail in the coffin of an industry that is slowly bleeding to death.

Daniel Kline owns shares of Apple and Microsoft. He almost never watches TV or movies on his phone or computer. The Motley Fool recommends, Apple, Netflix, and Walt Disney. The Motley Fool owns shares of, Apple, Microsoft, Netflix, and Walt Disney. Try any of our Foolish newsletter services free for 30 days. We Fools may not all hold the same opinions, but we all believe that considering a diverse range of insights makes us better investors. The Motley Fool has a disclosure policy.