We are checking the code of the plugin when there are security alerts about WordPress, to know if we are concerned or not, and if we need to do an update.
Usually, we are doing two or three updates a year, depending on security and feature issues. The updates are done automatically when the license key has been entered in the settings of the plugin. The updates appear on the Plugins page like any other plugin.
The updates are included during the first year. After the first year, a small fee will be ask to you to continue.