SharePoint2013 installing an app to multiple site collections

Scenario: How to install an app to multiple site collections

Resolution:
1)Navigate to your "appcatalog" site
2) On Quick Launch click on "Site Contents"
3) Click on "add an app"
4) Select an app and add it, wait until it installs.
5) Now from Site Contents page hover over the app. You should see below screen.

6) Click on "Deployment" as in above screen shot. The "Manage App Deployments" page opens up as in below screen shot.

7) Enter "SiteCollection" URL and click on Add. You can add multiple Site Collections URLs.
8) And finally click ok. Now your app will be installed to multiple site collections you specified.