Over the last four decades, the grotty share house has become an Australian rite of passage for poor university students. But while the best share houses are lively mini-villages, the worst end up in wars of passive-aggressive notes, bedroom dinners, and broken leases.

It was a good house heading downhill in 2006 that first gave Jules Malseed-Harris the idea for his new app, Fairshare. His home, a renovated doctor’s clinic in East Melbourne, housed seven people. Early euphoria had given way to the tragedy of the commons: piles of dishes and pots a metre high, cheddar turning into blue cheese in the fridge and tensions mounting.

Fairshare's Jules Malseed-Harris (L) and Oliver May.

Malseed-Harris examined the problem. Why did people clean their own rooms – but leave the communal areas to rot? The answer: a lack of incentives. So the young economist created a system in which each housemate had to earn a monthly tally of points – but had total flexibility on what they did. Plus, each housemate could see what the others were doing. Amateur chefs cooked, broke students cleaned, and the money-minded went grocery-shopping. The social engineering system went through iteration after iteration, until it worked smoothly. “The house began to hum,” says Malseed-Harris.

In early 2013, Malseed-Harris and his old school friend Oliver May took a leap of faith. Both had left their jobs in finance. They wanted something more – the chance to solve an everyday annoyance. And so the duo set about turning the house system into Fairshare, an app aimed at almost a million Australians who live in shared accommodation – and the millions more in America’s college towns and universities in Europe and Asia.