Click the compare option on the left menu and search for the application\service you want to compare with.
After you found the service you were looking for, on the top left you will see the
"Add a service to compare" button. This will allow you to search for new service for comparison. SkyFormation will also suggest similar services for you to choose from.
Note that services that are in use in your company will have an "in use" label next to them.