Before you commit to purchasing a full license of the INK plugin for Adobe Illustrator, you can leverage the option to try it for free. For Adobe Illustrator, we offer two options by default. An unregistered trial called "Preview" and a registered "Trial".
Free License gives you a sneak peek to some basic features of LTTR/INK for Adobe Illustrator for as long as you wish.
To leverage Free Licence you don't need to do any registration. It is always free, and there is no limit to how long you can use it. However, the available feature set is limited to drawing two paths and two stroke styles.