For the first 30 days since download, you can use the full version of Applications Manager. This version will allow you to explore all the capabilities of the product. If the full version satisfies all your monitoring needs and you are pleased with the improved performance of your servers, you can opt to purchase a commercial license. If not, after the first 30 days, your edition will revert back to the free version.
When you install the product, you can choose to evaluate either the Professional or the Enterprise Edition for 30 days. After your 30-day free trial ends, your installation will automatically convert to the free edition unless you apply a commercial license.