Thank you for posting to the forums! I understand you are having issues connecting the SlingPlayer app to the Roku and getting video to stream, I would be happy to help with that! I did see that you have multiple Roku devices in your home, when you connect on the SlingPlayer app and launch the connect to Roku icon you should see a list of all the Roku devices on that same network. The case may be that the phone is actually connecting to a Roku but just not the Roku that you were expecting. To answer the question regarding support the support period would be tied to when you purchased the phone app.
Here is an article that may help:
Hope this helps!
The Sling Moderation Team - Leanne