While I'm not usually a fan of free-to-play RPGs, I think Sdorica is one of the exceptions. Rayark did a fantastic job with this one, from the visual art style and sound to the interesting battle mechanic and tons of content for free, no strings attached. They also give you a ton of goals to complete for free premium currency, so the in-app purchases for more are more like a way to say thanks to the developers for making such a good game. It's completely optional and not necessary to play the game, but I can see myself spending a few bucks in the future to just support Sdorica. I highly recommend giving this game a chance if you're a fan of JRPGs.