GeoGebra is a great product and the community of people that have developed it do some amazing things. In my own experience, I felt there were times, say with younger or struggling students, where GeoGebra and other dynamic construction software was too abstract. It's a great goal to get students to this conceptual level, but getting there might be difficult. I feel that one way is with the kinds of manipulations (folding, cutting, etc) and transformations (animated, a little more tangible) that Tabula encourages. That's a big part of why I wrote it. I had to stop teaching to do it, so I can't quite make it free.

I understand what you are saying, totally agree with you and wish you luck with it. You made a really nice piece of software.