As a purist I've always battled with the thoughts of using a mobile phone as an artistic tool. For many years I've used my iPhone as a visual sketch pad / diary when I'd explore new locations, taking photos from possible vantage points to see how framing would work or just to have a visual reference of a location.
On cleaning out my iPhone photo library and backing them up I realised some of these images were worth editing and displaying online. It was important I kept to my principals in that the images had to have artistic value and be of a high quality.
Also all editing and online publishing had to be done on the iPhone and this is where Instagram proved to be the ideal platform.
The iPhone will never replace my Nikon camera for my main work. It is a tool to explore a new creative outlet and keep my work evolving.