try going to verizon.com/fiostvonline and logging in.
select a title and see if it will do the instant streaming through the browser.
Also with the APPS - I believe you have to log in, so if you haven't logged in while in the APP then try doing that. The app's only let you watch things that you have purchased though, from what I understand. I don't think those apps do the Free VOD stuff.
You can also look into the following
HBO GO
MAX GO
EPIX HD ONLINE
SHOWTIME ANYTIME
TNT AND TBS