I tested the adapter on the Nikon D3300 in combination with an HTC One m8 - Android 4.4.3 and an iPad with iOS7
You just have to install an app from Nikon on both devices; Wireless Mobile Utility.
The adapter is immediately recognized on the camera, so you don't have to do anything.
To make a connection, you must disconnect your WiFi connection (if you go online via WiFi) and then manually indicate the Nikon transmitter.
Then you can continue to take Photos and view photos via the app.
I've only taken pictures a few times. I don't think I'll be using this function very often because you can't really set anything besides 'just push'. So you have to set everything up on the camera itself beforehand and you can actually just as well use the self-timer/timer. Although I can imagine situations in which this can be fun, that you take the photo via your smartphone or tablet.
Very handy and the main reason I bought the adapter, transferring photos without the need for a PC, card reader or cable. This works great and I think it goes pretty fast too. Moving 1 photo or several photos works perfectly. A separate folder is even created on your smartphone/tablet. 1 disadvantage of this, by default the folder is on your internal memory, while I would have preferred to see photos on the SD card. If you have a smartphone with limited internal storage 4GB or 8GB - I think this is a problem.
A disadvantage of the app is that it has to be 'forced to stop' on my smartphone, otherwise the app will remain active. - What I don't like -
I have not yet tested the wireless range as other users mention here. But if this would be about 3 meters, this would still be enough for me.
The supplied storage box is a plus, you can attach the adapter to the carrying strap of your camera. That way you always have it with you.
Conclusion: excellent device, a bit pricey, but if you have a DSLR camera of 500-800 euros you won't fall over 50-60 euros. However, there is still some work to be done on the app, some things could be a lot better.