They are simple, yet they express a clear idea. For example, the car with the cord represents a hybrid/electric car. the color scheme also works well with the theme. The blue and green seem to represent nature and harmony.
Interface Action Arrows Types related vector icons.
Here are free iOS 10 icon set that will help you for next UI design project. This icon set contain 6 vibrant and lovely iOS 10 concept icons. You can use the colors as reference when you build your own iOS icon, because they fit well with the new design.