Not sure what Subway Surfers is, but you don’t really need any plugin for Unity. If you want to publish to iOS, you need a iOS license (if you want pro, you also need a Unity pro license), that’s all.
The steps involved are importing your objects/textures etc into Unity, write the scripts, put together some levels and then let Unity compile the game.
For the controls, have a look at the search here, Google, etc.
Also, this is not really a forum. This is meant for questions that can be answered, preferably quick and definitive (no opinions, etc.) If you want a real forum, we also have one of those here, easily accessible with the small link in the header, labeled ‘Forums’. Your question would probably be better suited there.