Hi Andrew,
Tobii has no concrete plans of building a high-level EyeX SDK for Android in the short term. I know there are others who would be interested in such a library for Android, so there is probably room for some sort of open source project. For Android there are standardized ways to read the window content (for example with an Accessibility Service) and you do not need to care about overlapping windows, so the implementation will most likely be more straight-forward than on Windows.
Good luck with your project! Please let us and the community know how it goes.