With smartphone adoption rising across the developed world, the global race is on to figure out what exactly the 'mobile wallet' does – and how it can improve customer experience. McDonald's is rolling out mobile payments across the whole of France.

News that McDonald’s profits fell 21% in Q4 2015 highlighted how the brand had lost touch with consumers. Trials in Australia and the Netherlands aim to make the brand relevant again, but can customisable menus and more comfortable restaurants bring people back through the golden arches?

On the outside it looks like just another café. But the hipster-looking diner named The Corner in the inner-city Sydney suburb of Camperdown is actually a 'learning lab' for McDonald's. And it's a smart way of providing feedback on a new trendy menu for the fast food giant.

With McDonald's challenged by fast food chains like Chipotle and Subway – which emphasise fresher ingredients and let people choose what goes into their products – the burger chain is expanding the "create your own taste" option. But can it boost sliding sales?