I originally thought the 30mn trial was a one time thing, which seemed very impractical for evaluation purposes.
Then I read this: https://news.ycombinator.com/item?id=8478545 and understood the 30mn are not a single time upon installing the software, but every day, and that apparently it is possible to choose when to start the trial. Which is indeed much better.
It would be a good idea and very beneficial for you to make it clearer on your homepage, like this for example:
In the basic edition of Boxifier, all premium features are available for you to try, every day and at anytime, for 30 minutes. This way you can see if Boxifier really works before deciding to upgrade. We believe you should purchase a license only if you are completely satisfied with the product. That’s how software should work.
That being said, I have just installed Boxifier but can’t find how to start the 30mn trial…