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This app is available under the terms of a fair use policy. You can use the demo for free - as in free beer - provided the usage is within reasonable limits.
You cannot (re)sell this app or copy the concept without the express written consent of the researcher/designer/producer (Pieter van Prooijen, Wereldopener).
The provided fair use is reciprocal: within reasonable limits Wereldopener keeps (1) this app available and secure and (2) your data private.
Usage is at your own risk and responsibility. By using this app you agree Wereldopener cannot be held responsible in any way for what ever.
This app uses models of third parties, mostly based on work of scientists. Wereldopener has endeavored to trace - and link to the sources of - the original developers of models and theories. If you believe you are entitled to rights regarding textual or visual material, please contact us.
The current demo app is available under Creative Commons license BY-NC-SA .
Other licenses are possible upon your request. We'd love to hear your wishes via
We reserve the right to make changes to this statement. It is advisable to consult this statement regularly so you are aware of these changes.