Currently not possible.
Both hyperPad and the graphics engine are 100% native iOS. This allows us to get maximum performance and work faster since we don't have to factor in other devices.
Our long term plan does include having users export for many other platforms. But we're just not there yet. It would take roughly 10 months of work just to get the player side cross platform (not the editor). Which really is not bad, but this means we wouldn't be able to work on anything else during this time.
hyperPad would essentially be dead in the water for almost a year while we do this change. Our goal is to get hyperPad and the community to the point where we can sort of be hands off for a little while and make this change.
We're getting close, but not quite there yet. Maybe something for 2020?