It took quite a while for me to receive this as it comes from China, but it is definitely much better than paying £30 for Nikon's official remote shutter release.
It wasn't working for me at first, however I soon realised that I had to push it into the GPS socket much further (basically, I hadn't plugged it in properly). Before you first plug it in, check which way round it needs to plug in as the GPS socket is very badly designed - unlike USB where it can only go in one way. There are no settings to configure, simply plug it in and it works.
The device is well built and although I've only used it a couple of times, I'm sure that it will last a long time. The button on it works like the camera shutter button - press it half way to focus and all the way to take a picture. If you're using bulb to take a picture with a custom exposure time (or want to do a lot of continuous shooting), you'll want to slide the button up to lock it after you've pressed it - this allows you to keep the shutter pressed, even though you don't have your finger on it. Very useful for 10sec + exposures (like astrophotography).
Overall a great product and I would definitely recommend it over Nikon's official one because of the price and build quality.