Thanks for posting in the forums! I'm sorry to hear you are having trouble connecting remotely via HTC one with the SlingPlayer for Android Phones application.
Were you able to connect from a remote location with you Samsung Galaxy s2? If not, your Slingbox may not be setup for Internet viewing.
Below are articles that explain what needs to be done:
For the 350 or 500:
For older models:
Hope this helps!
The Sling Moderation Team