An app created using a map seized from Islamic State was a "game changer" in the battle to defeat the extremists in Raqqa, a British man who fought the murderous group has said.
Macer Gifford spent three years fighting alongside the Syrian Democratic Forces (SDF) in a bid to help eradicate the jihadis after they swept across and took control of vast swathes of Syria and Iraq.
Speaking to the Press Association, the 30-year-old said he understands the app was put together by the Americans using a very detailed map of Raqqa that was captured from IS.
Mr Gifford said the app did not have a name and was just something they had at their disposal, and described it a "massive game changer" in the battle to defeat the extremists in the city.
Discovered on the computer of an IS commander, he said the map had been created using drone images taken from height that were then stitched together.
He said the GPS template was then added to this, along with icons that could be dragged onto it and which allowed the information to be shared amongst those battling against the extremists.
"It was a very simple app, and it was something that all the SDF people could have and it meant even the most untrained man in the world could call in an airstrike," Mr Gifford, who uses a pseudonym, said.
"I would be walking down the street and would take fire from a building or I would see enemy movement or a tank, all I'd have to do is move my dot, get the grid co-ordinates and call it in."
A former banker who worked in foreign exchange before heading out to the Middle East to fight alongside the Kurdish militia (YPG), he said he got the app early on in the battle to retake Raqqa.
"I didn't just use it for airstrikes, in fact I mostly used it to understand my position within the city - it was sometimes very confusing," he said.
Mr Gifford said the information could be used to establish where other YPG units were, identify safe places to run to, and possible routes suicide vehicles that could be driven at them may take.
Allowing users connected to the internet to share information easily, positions of enemy fighters could also be marked on it.
Mr Gifford fought against IS in every major battle and has previously said that he was motivated to do so because of their "butchery".
He described the skies above Raqqa as being full of American aircraft and how on looking up there would be a dozen drones and F-16 jets "just circling the sky".
"Their coverage of Raqqa was 24/7, it was incredible - there was barely anything that could move in the city without being watched at some point, or without being seen," he added.
Mr Gifford said introducing technologies such as the app into a local force "is what wins modern wars against groups like the Taliban and groups like Isis".
Quizzed on whether the Americans ensured they were hitting a valid target before striking, he said "sometimes it would be hours before there was a bomb", but that if there was an airstrike, the feeling amongst his unit was that they had been right.
Pressed on whether he thought the app was a key part in the fight to liberate the Syrian city, Mr Gifford said "massively", with the ability to know "exactly where things were".
"The real way that we won in Raqqa was that there was more of us, we completely surrounded the city and that meant we could attack from the north one day, the south the other," he added.
"Isis had no idea where we were going to come from.
"On top of that, a spy network inside the city and also the constant, constant surveillance meant infrastructure within the city - command and control centres, logistics points, barracks for men - were constantly being hit.
"That destroyed their ability to really effectively move men around and have a coherent defence."