The Triggertrap web page states that for a Nikon D3200 you need a MC-DC2 adaptor for use with an iphone etc, please research/scour the internet to get the right set-up diagram/schematic for your Camera. Also don't forget you need a donor plug to attach to the MC-DC2 port in your camera.
I have found the pin layout for a Nikon D3200 as here:-
Please observe caution when making this equipment, as I will not to be responsible for your connection errors and damage, to either a phone or camera!
So my transistors just came in the mail, opened up my push-button shutter release to see what makes it tick and it appears to have a 2.5mm socket linked to ground on the end which is odd.
To save me ripping the connector off, I'll just string some extra wire out the back hole to utilise.