Apple's new TV app is pretty awesome for the subscription apps it supports.

Too bad it doesn't include Netflix, HBO Go, Watch ESPN, Sling TV, The Disney Channel, Nick, PBS or many others already available on Apple TV. (Oh, and Amazon Video, which still isn't available on the box.)

Likewise, single sign-on is flat-out great -- if your service provider is supported. The novel companion feature allows you to discover new TV apps you're already subscribed to and activate them automatically, without entering usernames and passwords over and over. Too bad it it doesn't support Comcast, Spectrum (formerly Time Warner Cable and Charter) or Verizon Fios.

I've spent some time playing with the new TV app and single sign-on, Apple's newest additions to both the Apple TV box and iOS devices like the iPhone. My first impressions? They do make it easier to find and watch (and binge) the shows as well as movies you get "for free" as part of a subscription, as long as the service that unlocks those shows is supported.

If Apple could get more must-have apps and providers to, uh, sign on themselves, the Apple TV box really would make the bewildering world of app-based, internet-delivered TV a lot easier to use and understand -- and differentiate itself from the Rokus and Amazon Fire TVs of the world. Until that happens, however, you're still stuck doing the grunt work yourself.

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The dream: All your TV in one place

What do I mean by grunt work? If you're like me you already subscribe to Netflix, Amazon Prime and cable or satellite TV -- which means your subscription grants you access to "TV Everywhere" apps such as FXNow and Watch ESPN at no additional charge. Or maybe you don't subscribe to cable and use Hulu, Sling TV or maybe your parents' HBO Go password.

Today when I want to find something new to watch "for free" as part of one of my subscriptions, I have to go to a bunch of different places. I might check Amazon's app for Prime stuff, and if I don't see something I like I pop over to HBO's app. Then, if nothing's worthwhile there I check out the Netflix app. Browsing each one for a "free" movie or TV show I actually want to watch is a pain, and sometimes I just settle for something lame, or bite the bullet and pay to rent a new release.

The promise of Apple's TV app is that all of those mini walled garden searches go away. Instead, you browse all that stuff in one place. Friggin' awesome.

David Katzmaier and Sarah Tew/CNET

No more middleman for supported apps

When you install Apple TV's latest software update, a message appears describing a new function for the Apple TV remote's TV-shaped button: It gives you direct access to the main Up Next section of the new TV app. Clicking it brings you into the app, where you're prompted to "connect apps" by entering your Apple ID.

From there it's easy enough to integrate supported apps you subscribe to. In fact, just using such apps causes a permissions screen to appear, asking if you want to integrate the app into the TV app. The top "Store" section links to all the apps that work with the service under "Start Watching Now" and "Watch with your TV provider." If you don't have one of the apps listed there installed already, it's a great place to find new ones.

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Once you've signed in and given permission to a few of the apps, the TV app fills itself up with shows and movies from individual apps under the main "Watch Now" page. Every item on this page is customized to you and you can watch it right away, either because you subscribe to the service that has it or because you bought it already. That's the best part of the TV app: Nothing on the screen is designed to get you to buy it. It's all stuff you already have access to.

The top section of Watch Now, called "Up Next," lists the last few shows or movies you've watched, regardless of the app they came from. It's really well done. Moving over each show or film changes the background image, and a readout in the upper right says "Continue" (allowing you to resume where you left off) or "Next Episode" (if you finished). Selecting one drops you right into the episode where last you left off, with the option to start from the beginning, or you can start the next episode. Aside from a brief splash screen for "Hulu" or "The CW" or whatever, the TV app skips the app's main interface entirely.

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Below "Up Next" the TV app has "What to Watch," which suggests popular individual shows and movies, "TV spotlight," "Movie spotlight," a dedicated "Browse by Category" line with TV Shows, Movies, Kids and Collections, and more collections below including "TV's Biggest Shows" and "Riveting Drama."

Selecting something takes you to the show page, where the default is the main service that offers the show for free. Another option, "Open In," lists secondary services that also offer the show. If I wanted to watch "This Is Us," for example, Hulu was the main option for me, but I could also see it in iTunes (paid) or on NBC (with commercials). The default option was best for me.

The TV app's top line menu has three other options beyond Watch Now. There's "Library" (which shows iTunes' TV shows and movies), "Store" (with promoted shows and apps, more iTunes content and the available/linkable apps noted above) and "Search" (a universal TV and movie search with voice support that also hits apps like Netflix that aren't included in Watch Now). But the main innovation is Watch Now and its easier-than-ever access to your own stuff.

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Continue watching on your phone

The TV app is also available on iPhone and iPad devices, and it's mostly the same. One big difference, aside from the bigger thumbnail images for shows and requisite need for more scrolling, is that Library (which contains your iTunes stuff) is the primary menu item, not the more innovative Watch Now.

The TV app automatically syncs across devices that use your Apple ID, so you can stop watching a show on your Apple TV and start again on your phone. All of the Up Next shows appear there too. If you haven't installed a particular app on a device, you'll be prompted to do so. While an Apple TV box and a big-screen experience are the natural home for the TV app, having access and continuity on mobile devices is pretty cool too.

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The state of support: sorta sorry

As good as it is, the TV app doesn't solve my grunt work problem because even though I subscribe to Netflix, HBO Go, Watch ESPN and The Disney Channel, none of the shows from these providers appear inside it -- even though they have Apple TV apps.

The same goes for Sling TV, DirecTV Now and PlayStation Vue, as well as the myriad sports (NFL, NBA TV) and news (CNN Go, ABC News) apps available on Apple TV. And then there's Amazon, which lacks an Apple TV app altogether, as does Vudu and Google Play Movies and TV.

The TV app does support a total of 37 apps at launch, including Hulu, HBO Now (the standalone version of HBO Go), Showtime (and Showtime Anytime), Starz, CBS All Access, Comedy Central and FXNow. Click here for the full list.

Then there's single sign-in, the Apple TV feature that launched a few days before the TV app. In my testing it mostly works well to eliminate the need to sign in to individual TV subscription apps, but the real problem is (again) the lack of support. It currently only works with a handful of TV providers, excluding the vast majority of the American cable TV audience.

David Katzmaier/CNET

Apple says it's working on adding more support to both the TV app and its single sign-on feature, and I believe them. The bigger question is whether it can land the true whales in each space: Netflix and Amazon for TV apps as well as Comcast, Spectrum and Verizon Fios for single sign-on.

Apple deserves credit for taking on some of the most annoying problems of the TV app world without pushing its own service (iTunes) too much. With the TV app and single sign-on, it makes the Apple TV box and iOS devices even better for TV fans, whether you're a cord cutter or cable subscriber. If Rome wasn't built in a day, then neither was an easier way to watch "Westworld."

Disclosure: Note that CNET is owned by CBS, which is a compensated programming provider on all cable, satellite and online TV services that offer CBS channels, which include Showtime, Pop, CBS Sports and The CW, among others. CBS also owns and operates its own online service, CBS All Access, which is mentioned in this story.