Single post in Browser-specific features (previously Chrome-only)

I was able to download it and when I go the extensions page it is there and enabled. However its not appearing on my chrome, I have shutdown chrome and my computer twice to see if it would work. If anyone could help me figure out how to get it to show up it will be greatly appreciated! NOTES: I have never used an extension before and I have a MAC (this is probably why its not working)