The license system is built by Atlassian. They give the following answer:
"Marketplace app customers can get developer licenses for apps just as they can for host Atlassian products. Developer licenses are intended for staging or development environments only. Customers who have purchased Marketplace apps can get developer licenses by clicking the View Developer License link from their license page on my.atlassian.com.
The license types between the app and host application must match. That is, an app with a developer license only works in a host application that also has a developer license. The same applies to production licenses—a host application with a production license only takes apps that also have production licenses. If an app license type doesn't match its host application, the Universal Plugin Manager reports a license error status of Incompatible with product license (wrong type) for that app.”
Read more: How to create developer licenses