I started on an android version a few months back, got it to the point of logging in and showing the list of characters, but that was it. Recreating the UI from scratch is quite a large undertaking, and there are many areas that I still don't have any good solutions for. The other problem is that I wouldn't do an apple port, due to their ridiculous (and yearly) fees to even have your apps on their app store (and the fact I own no apple products). Other concerns are things like speed, higher latency from phone networks, etc. Plus, I still have a crazy amount left on the main version of the game, so this would detract from that (though I would argue not necessarily needlessly, as it has it's own benefits). Most likely any initial releases would be on the order of getting all the various proficiencies working, and then moving onto more complex things after that. Still, even that is more complex than it sounds, because the entire item system has to be put into place before even that will be workable, since all skilling proficiencies are based upon items.
All that said, I haven't tabled the idea, just that it's very low priority.
So... maybe someday?
