Many of the ESRI demos have this as a feature. You have a handle that you can drag across the map (left-right). As you "swipe" from one side to the other, the top layer is "peeled back" to reveal the layer under it. If you stop in the middle, you'll essentially have a split screen showing 2 layers.
Thanks for the link. But it looks like the 10.2.7 version has a Thumb class to support the swipe operation. Unless I'm missing it, the 100.x runtime doesn't have a Thumb class.