Safetipin, a map-based mobile safety app, is one of thousands of projects being rolled out in cities across the world as part of a United Nations initiative to stem cases of rape, sexual harassment and molestation in urban areas.
Designed by the charity Jagori, Safetipin uses crowd sourcing to rate the safety of areas in Delhi based on factors including lighting, population density, transport and gender diversity.
It also acts as a personal GPS tracker, allowing users to be tracked or to trace a loved one.
From New Delhi in India to Port Moresby in Papua New Guinea and Quito in Ecuador, a small but growing number of municipalities, charities, companies and community groups are joining UN Women's "Safe Cities Global Initiative".
"Unsafe public spaces limit women's and girl's life choices. This daily reality limits their freedom to participate in education, work, recreation, and in political life," said Laxmi Puri, deputy executive director of UN Women.
"In many cities, adolescent girls are afraid to walk on their own when they go to school on the streets in their own neighbourhoods because they experience various forms of sexual harassment, such as cat-calling, stalking, whistling, touching."
One in three women globally have experienced either physical and/or sexual violence, according to UN Women.
While many countries have in recent years strengthened laws and improved infrastructure to curb sex crimes, efforts have lacked a coordinated, focused approach - and are rarely assessed for their effectiveness, experts say.
Rape city to safe city?
A burgeoning metropolis of 25 million, Delhi and its environs gained notoriety for sexual violence after a young woman was gang-raped on an unlicensed bus in December 2012.
The attack, and the victim's death from her injuries sparked widespread protests and increasing awareness of the problem.
As a result more women are reporting abuses, say charities and the police. There were 2,166 reported rapes in 2014 in the city against 1,636 in 2013 - a rise of 32 % - according to police data.
"There are areas where I feel safe like around busy markets where there are lots of restaurants, but there are many areas where it's really scary," said Reshmi, 22, a student, outside Green Park metro station in South Delhi.
New Delhi is now one of 25 cities including Port Moresby, Quito, Kigali and Cairo to have joined the safe cities project. Some of the initiatives so far include boosting street lighting, installing toilets, setting up helplines and strengthening laws on sexual harassment.
Each city first does a "scoping" survey on perceptions and attitudes towards sexual violence which is used to develop city-specific programmes that are evaluated every five years.
In Delhi, for example, the first study done in 2012 found that 90 % of women had experienced sexual violence in public spaces and only 5 % felt safe in the city.
Using these findings, authorities, charities and others can work out specific initiatives to address women's safety.
As well as the introduction of mobile apps like Safetipin, programmes that encourage men and boys to think about sexist behaviour are also being carried out.
At the same time, the authorities are installing CCTV cameras in buses and police stations. They have also ordered taxi firms to have GPS systems in their cabs, and set up fast-track courts for sexual violence, amongst other measures.
Upgraded markets, safety audits
Other cities are also taking up the challenge. For example, in Cairo, the ministry of urban planning has adopted women's safety audits to guide their development plans.
In Papua New Guinea's capital, Port Moresby, authorities have upgraded a market where more than 80 % of the vendors are women. They have build new infrastructure, including bathrooms and showers, renovated market stalls, provided access to potable water and established a vendors association.
Municipal officials however admit that ending sexual violence is not just about creating infrastructure, but also about sustained public campaigns that dispel sexism and challenge gender stereotypes.
"In the city of Kigali, every new paved road is accompanied by public lighting. This has contributed to a safer environment in which women can work in the evening and night hours," said Hope Tumukunde, vice mayor of Rwanda's capital, at conference on safe cities in Delhi last week.
"But we are also using artists to deliver strong messages against sexual harassment through a popular singing competition. Such strong messages can go a long way towards changing sexist attitudes and it will ensure more prevention than retribution."