from "videos" to "tv"

You will want to look in the "Store" section of the TV app. There you will find a list of apps that work with it. You will have to download each app individually. To access the content of these apps using the TV app, you will need to sign in using your cable or satellite provider. I've been able to sign in to all of them without sighted assistance but it wasn't easy. Almost all of the apps are not very accessible with voiceover and many buttons are unlabeled. But once you find the sign in area, it's usually not too bad to get signed in.
Once you have successfully signed into an app, you then need to go back into the TV app. Go to the "Watch Now" section. It will have recognized which apps you have signed into. It will ask you if you want TV to access those apps.
Once you've done this, the TV app will start pulling content from those apps. It will tell you all kinds of information about shows like when they air, how many seasons, who stars in them etc. etc.
If a show or movie is available from more than one app, it will tell you that as well. And it will give you the choice of which app to use to view it.
The other problem is that you don't view shows within the TV app. This is a problem because, again, most of the apps are not very accessible. So player controls aren't easy to use.
It is very useful though for tracking your iTunes library.

Hope this helps a little. Like I said, I've connected all of the available apps to my Dish account. So I can hopefully answer any questions if anyone has them.

One last thing, not all of the apps are using the single sign on method. This is unfortunate because it worked very nicely for the apps that did.

I wanted to point out one other thing.
Many tech sites and podcasts have said since the beta and even now that the new TV app does not work with Netflix.
This is not entirely true. It may not offer original programs from Netflix but it does offer the Netflix versions of network shows.
For example shows like The Walking Dead or Pawn Stars are available from their network apps. But their Netflix versions are also available. Most of the shows from the network apps seem to be just the current season. When available, you can access additional seasons from Netflix. The app is really good at telling you what content is available from which app or service.

I hope that clears up things a little more concerning Netflix and the TV app. I listened to IOS Today from TWIT last night and they emphatically said that there was no Netflix content in the app. So I thought I would add this clarification.