I would happily plunk down $15 for an Android version of Stardew Valley. Heck, I'd pay even more if it made it a reality! (Kickstarter, perhaps?) I just don't get as much quality time with my aging PC as much as I do with my lovely smartphone. I've enjoyed watching my roommate play Stardew Valley, but I won't be able to buy it until it's ported somewhere else. And I probably won't play the heck out of it unless it's ported to smartphones or maybe the 3DS. How can I get my voice heard?
It is very unlikely to happen now. The game was written in a library designed for Xbox 360, the fact that it works in Windows in first place is already very good. Making it work in mobile won't really work easily, it would be massive amounts of work.