I downloaded the Sling app for my Atv4 but can't figure out how to sign up as a new user. The app acts like I am a returning member and asks me to log on and enter my password.
Sign up at Sling.com
Sling doesn't offer sign-up through the app in order to avoid Apple's 30% cut of the subscription fee each month.
On a small side-note: Whenever you're about to sign up for a subscription through an iOS app, always check the company's site first to see if the subscription costs less than what it is actually offered for through the iOS app. Examples of this are apps like Spotify, and Hulu Plus for the ad-free sub.
You're welcome
So I signed up for the free week trial offer, and so far it's pretty good! I don't have a super fast internet connection but it plays without any slowdowns. I'm not a fan of the user interface, but so far so good!
Home internet is on TMC at 15mbps. Using SlingTV on the Apple TV. So far its going pretty well. I tested it on a chromecast v1 and v2. off and on both would be choppy and pixelated.