You may continue using Kurviger 1 Pro.
(it will be maintained for new Androids)
If you need new features you can upgrade to Kurviger 2.
The model Free/Pro is no longer sustainable, for further development, third party services,
maintenance, hosting, servers, etc.
If we continue with it, Kurviger will stop to exist. Therefore subscriptions exist per platform.
There are more details in the related topic: