Difference Between Blog App & Blogs in Group

Hi, SI Team

I made my first post in a group:

Whilst not logged in I go here:

http://finalbug.net/groups/item/17-learn-fcpx

Under Apps if I click on Blog I am directed to login.
Under Blogs in Group I am taken to the Blog Post.
http://finalbug.net/blog/entry/482-001a-fcp-x-first-steps

Also the Blog post shows on the Blog (which I want)

However I would have thought that this behaves the same way across the site.

I guess my question is do the Apps only work whilst logged in?

please advise

Paul