To install the app, you must:
Log into your Confluence instance as an Administrator.
Navigate to
...
> Settings > ATLASSIAN MARKETPLACE
...
> Find new apps.
Enter the name of the Bob Swift Atlassian app you want to install, in the search box.
Click Try it free to begin a new trial or Estimated 'price' / month to start a free trial for a month and convert to a chargeable licensed version for the mentioned price.