Thanks for asking 😉
All pre-releases (all alpha and beta releases) will always be free. When we do release the finished version, however, after a while the pre-releases will at some point stop working.
You can then chose to download the finished version (Animation Paper v5.0) which will work as a free trial (for 14 days). If you decide to buy a license (our introductory offer will be $79 usd one time fee), you will own this lifetime license – not a subscription – including free point-updates (5.1, 5.2, etc).
Do you think this is all fair?