App: Switch to pay-as-you-go licensing

[rumbrummer]

@Zoran

What do I need to run Kurviger 2?

As far as I can see Kurviger 2 is in beta phase yet, →

1. Take part in beta program
   Kurviger Beta program
2. Install Kurviger 2.0.7
   Kurviger 2.0.11 (Beta)
3. To get all features do a subscription inside Kurviger App