first, lets be clear about Micropython, the software versus PyBoard, the reference hardware. Micropython on a Pyboard is runnunig on bare metal with no OS. Micropython is very portable, and builds nicely on Linux, yielding a nice small-footprint Python. I am not aware of a build for Android, but it seems like it should be straightforward. Everything about Micropython is tuned for low memory footprint, so it might be a great tool for Android aps.