picsman Loc: Scotland

I take a lot of amateur sports in competition with other photogs. It is a rush to get the images online to the same website and who uploads first gets the "worm".

So to speed up the process how can I use my D750 wifi to instantly upload my pics to a phone or tablet and then delete the unnecessary images and then upload from the iPhone or iPad to the website?

I know that the Nikon software can be used to receive the pics from the camera but how does this work in practice? Has anyone uploaded from an iPhone/ipad to a 3rd party website?

Any and all help and guidance gratefully received.