Notice that the keyboards are in development state, and therefore can change at any time. For the latest version and the changes, please refer to the changelog.
Current version 1.0 (January 2020).
Javanese script fonts are numerous. The most widely used one is Noto Sans, but Google botched the font and created public outcry. They fixed the font, but hasn't published it yet. You can download it and other fonts here:
Other useful pdf. Among them are: