Social enterprise Memeza co-founder Elmarie Pereira has been tackling South Africa’s alarmingly high crime rates one panic button at a time since 2012. A gender violence-based attack on her sister catalyzed Elmarie to develop the first public alarm safety system linking victims of crime to community and policing forums. The alarm app, aimed at mid to low-income communities, works via SMS while the handheld device emits a sound of 140 decibels to alert passersby. Memeza has partnered with 210 police stations, 345 community policing forums, and numerous corporate social responsibility programs, which have all documented significant drops in crime.