I have an app on the App Exchange. I know the LMA is used on the app owner's side to control who can/cannot use their app based on the allotted licenses they've handed out per installation. From the docs, is it as simple as associating "a package with the License Management App"? Is there nothing more that needs to be done?
Yes, once you've installed and linked the LMA to your managed package, you can specify, per org, if they have a limited number of licenses, or a Site-wide license, if the license is in Trial, Active, or Expired status, and an expiration date. You can even write triggers, workflows, etc on the object to automate the process, as well as specifying default values. If you do so, remember that adding validation rules, etc can potentially break the system and prevent proper licensing.