Bhanuben lets out a throaty laugh when asked if the men of Dharavi are scared of her and her team. “Not yet ... but they are a tad wary of us these days,” says the 42-year-old community worker for SNEHA (Society for Nutrition, Education and Health Action), a Mumbai-based NGO.

Mumbai’s Dharavi slum is home to anywhere between 300,000 and 1 million people. Bhanuben was born and brought up here and knows the place like the back of her hand, and the challenges of surviving in this “teeming slum of 1 million souls”.

“There is a high incidence of gender violence here, but I have been lucky,” says Bhanuben, a mother of two sons, adding: “My husband is a good man.”

Data from the National Crime Records Bureau shows that 43.6% of all crimes against women are by husbands and relatives

Violence against women is pervasive in India and much of it – domestic violence, dowry deaths, acid attacks, honour killings, rape, abduction and cruelty – is at the hands of family members. Data from the National Crime Records Bureau (NCRB) shows that an Indian woman is most unsafe in her marital home: 43.6% of all crimes against women are by husbands and relatives.

In multi-ethnic Dharavi, the problem is compounded by the fact that most women are poor and uneducated. The relentless pressure to survive, lack of space and unhygienic living conditions lead to malnutrition, deprivation and disease – and often abuse of vulnerable women and children.

SNEHA started working with women in Dharavi in 2001 and has since supported 300,000 women and mobilised 130 women’s groups to educate and support survivors of violence.

“While the number of cases of domestic violence has been increasing every year in the slum, we felt there was a gap in reporting of such incidents thanks to lack of a support structure and societal norms that force women to keep quiet,” says Nayreen Daruwalla, director of SNEHA’s prevention of violence against women and children programme.

To improve reporting of violence, SNEHA launched the Little Sister Project in 2014. Funded by the UN development programme, the project trained 160 local women to identify and report incidents of gender violence using Android smartphones that are loaded with an open data kit (ODK) form and an app called EyeWatch.

“Earlier we would write the case details in a register... it was cumbersome. But now with ODK, we do it electronically,” explains Bhanuben. The information is then stored in a central database maintained by SNEHA. The identity of survivors is kept private.

The EyeWatch app, which has been developed by a firm called Indianeye Security, is a mobile-based platform that allows the community workers, known locally as sanginis, to take audio and visual clips if they witness an incident. Once the app is activated and an alert has been raised, a call goes through to an SNEHA employee who can offer assistance.

“This technology helps us crowdsource cases of violence, track cases of repeat violence and understand more about the prevalence of violence in Dharavi,” says Daruwalla. “We believe reporting violence is the first step in preventing violence.”

Mumbai’s Dharavi is Asia’s largest slum and home to up to 1 million people. Photograph: Bethany Clarke/Getty Images

The app, SNEHA believes, encourages increased reporting of violence, lets community members know what assistance is available, and helps NGOs understand more about the prevalence of violence in Dharavi. The interaction is two-way: sometimes sanginis come to know about a case and approach the survivor; at other times, survivors seek out sanginis to report incidents.

“Our volunteers are trained to advise survivors on [the] availability of medical help and also on how to approach the police.” Once cases are brought to SNEHA’s centre, counsellors help survivors file police reports and offer legal support, says Daruwalla.

Earlier this year, SNEHA promoted its work at the inaugural Dharavi biennale. Using scrap denim pieces and discarded objects, sanginis created an art project called Mapping the Hurt, an innovative visualisation of gender violence in the slum.

But if tracking and reporting violence is one part of the challenge, the next big hurdle is getting the police to act.

“Whenever we go to the police to report on domestic violence, they are reluctant to file a case. They say such issues should be settled at home,” explains Bhanuben. Even if a case is lodged, low conviction rates strengthen the impression that there is little point in reporting the crime. Further, a lack of understanding of gender issues, violence and entrenched views about women’s status among lawyers and judges often encourages outcomes that favour reconciliations, overlooking a woman’s needs and demands.

Data collected from July to December last year by SNEHA showed that of the 345 cases analysed, only 19% were reported to the police.

The NGO’s outreach programme has trained 4,500 police officers and cadets in Mumbai and more than 2,100 public hospital staff to help them identify evidence of violence among patients.

Bhanuben says that along with being a support group, sanginis are friends with whom women can sit and chat. “Sometimes we go for an outing … to get some fresh air. To outsiders, this camaraderie may not mean much, but for us this is oxygen to survive in this challenging atmosphere.”