See the winter 14 Release notes
Salesforce apps are now implemented as connected apps and automatically installed in your organization.
Salesforce apps built as connected apps have been placed into two
managed packages – one for Chatter-related apps and one for
To simplify administration, each package is asynchronously installed
in your organization the first time any user in the organization
performs either of the following actions for any one of the Salesforce
apps in the package:
- A user accesses the connected app’s OAuth approval page.
- The connected app performs a refresh token flow for the app.
The packages are scheduled to be available for installation starting Friday, September 20, 2013.
The packages can be installed at different times, depending upon when their apps are accessed. This means that many administrators will see Salesforce connected apps (for example, Salesforce for Outlook), and the packages that contain these apps, installed in their organizations with no action on their part because they were installed automatically.
So as it is said in bullets if you try to access any of the app first time which is the part of this package you will see the package installed in your org if it is not installed in your org.
To install this package: I would suggest you to go to https://workbench.developerforce.com and login with your sandbox.It will ask for permission->allow that. Some time later after this in the installed apps section you will see that the package is installed.
FYI: I have verified this in my sandbox.