Roku app

Your question is somewhat confusing.

The U-verse app is compatible with:

• iPhone®, iPad®, or iPod touch® (iOS 9.3 and above)
• Android® smartphones and tablets (OS 4.4 and above)
• Android wearables (Android WearTM OS) Amazon Fire TV devices

If you're asking about The Roku Channel, (available on Roku) that's free.

If you're asking about the AT&T TV app, you must be subscribed to AT&T TV to use that.

That’s because it is confusing.  I have AT&T universe for cable and want to know if I can use that cable sign on for the att tv on Roku channel at atttvnow.com/Roku or if it requires a separate subscription.  I used to have TWC now Soectrum cable and could use my Spectrum channel on Roku to watch cable channels on a tv without a box and want to know if my niece can watch cable channels on her tv in her room like this....

Uverse and AT&T TV are two different services.  You cannot use your Uverse (note spelling) to access AT&T TV content.  Uverse is one TV service.  AT&T TV is a different TV service.

If a network is in your TV package and there's an app available on Roku, you can use your Uverse credentials to access those channels (except HBOMax since it's not available on Roku). 

Using my Uverse login, I can access apps for HGTV, Bravo, FoodNetwork, TLC, Showtime Anytime and other channels that I have on U450.

So your niece would have to use YOUR Uverse credentials (att.net email address) to access TV content that's in your Uverse package.