What is the license policy? License Key required ? On how many websites can I use Ulmod extensions?

Our License Certificate is valid for 1 live Magento installation and unlimited test Magento installations. No license key required.
Extension is not domain related, but installation related. If you run several domains on the same live instance of Magento, you can use one extension license. However if you run each website on a new live installation of Magento, you need separate license for each of them.
The full end-user license agreement is located here: https://ulmod.com/license-agreement.html