Okay so I really don't just want to say that it isn't allowed because it is smart and I see no reason for it to not be allowed. The problem is that it also doesn't seem completely fair, so I think it might be better to have separate subcategories? I'm not too sure.

My humble and a little bit biased opinion is that using a touchscreen device is simply a different/better piece of equipment. All runners have access to it, and if they want to buy it, they can. That's how it feels with a lot of other games, that whoever has the best equipment has the best chance. So I don't think separate subcategories would be necessary.