I downloaded half a dozen just to try out.
The FlyerHeroes template showed up as promised on my desktop. Adobe Watermark and Adobe Paper Textures, plus the $5 "Edge FX" all seem in order here in "My Add-ons":
Using Photoshop CC 2014 on a Mac Pro.
I've restarted Photoshop after adding the add-ons, but when I go to Windows>Extensions, the Extensions option is greyed out.
I have an early call in the a.m., so must sign off now.
If anyone can offer a suggestion or two while I am unconscious, it will make my day tomorrow morning.
Thanks in advance!
-robert