It's not hard since we have the code, you just have to port it (and it will be a lot of work). But keep in mind since Android apps run on a virtual machine - compiled RME is pure machine code, but apps are bytecode - it will use much more memory. So no, probably no if you want to edit anything bigger than 20 megabytes, at least not for now.
OTC is possible, since it is much lighter and smarter than the map editor, but I just can't imagine playing Tibia without keyboard hahahah