Traditional ND Grads are great filters, but they have two primary drawbacks. One, they can be tricky to align in the field. Secondly, they don’t work well for objects that protrude into the sky.
The Graduated Neutral Density effect filter in Nik Software’s Color Efex Pro 4 solves these problems, provided that you have an image that doesn’t have blown highlights. It has controls that let you create just about any kind of custom ND Grad filter, and it unlike real filters, this effect lets you brighten areas, too.
The big challenge with this tool is proper positioning. I’ve put together a short tutorial on how this filter works for landscapes.