If a user tries to view your ScreenSteps site via a tab in Salesforce and instead of seeing the help content they just see your list of sites it is possible that they are blocking 3rd party cookies in Chrome.

To fix this they can do one of two things:

1. Enable 3rd party cookies https://support.google.com/chrome/answer/95647, or
2. Add your ScreenSteps domain (youraccount.screenstepslive.com) as an allowed domain for 3rd party cookies. Be sure to replace "youraccount" with your actual account name. Look under "Allow or block cookies for a specific site" in the article above.