The Infinite Runner Engine is a Unity 2D+3D Endless Runner Kit, available on the Unity Asset Store.
It's a highly customizable, optimized and easy to use solution that will provide you with everything you need to create your very own endless game. It comes with a bunch of complete game examples, in various gameplay styles (platformer, lane runner, etc...). Completely mobile and other touch devices ready, it's never been this easy to create endless games.
I've created the Infinite Runner Engine alone, from sprites to 3D models through code and game design. It's been in the top most popular complete projects of the Asset Store since its launch.