I don't think anyone has looked at doing that yet. We'll be supporting custom levels in Eufloria HD PC/Mac/Linux from Summer 2013 and we'll look at our Android options in at least some unofficial way. There are too many issues in allowing official support with our current set up.
If we do Eufloria 2 we would look at reworking the system to support custom levels on all platforms. And an editor
Part of the current problem is allowing custom scripts to run on mobile devices - security risk/not allowed on Apple devices (unsure about Android). We can do away with that issue on mobile platforms while still allowing custom scripts on open platforms, but only in a sequel.
Back to how to do it on Android - if you have a rooted device, are you able to replace level files in the apk? If so, that's you're way in for now.
