As for a GTS app on an Android phone, that sounds very possible and like a very good idea.
However, something like that would use a ridiculous amount of battery- not to mention even a modded Droid will probably get in trouble with Verizon or the service provider.
Its not really something that EVERYONE could use.
As for the legality checker, I wouldn't use it. Unless there is pokesav for android? That would make my life way easier.