The main priority so far is to get the SDK working with mobile devices (both Android and iOS), but this priority can change depending on the needs of our supporters. Actually, we just included desktop support in our development roadmap.
We're glad you're excited about Android support. This is ready now and available here.
As for your advice, thanks! We really appreciate your feedback. In fact, the target price for the SDK in version 1.0.0, including support for HTML, Android and iOS platforms will be $39.99, but we're offering it at lower prices for our early supporters while it's still on development. Price will be increasing as we add more features, but all our supporters (early or not) will receive all subsequent updates free of charge.