Police interviews gather detailed information from witnesses about the perpetrator that is crucial for solving crimes. Research has established that interviewing witnesses immediately after the crime maintains memory accuracy over time. However, in some contexts, such as in conflict settings and low-income countries, witness interviews occur after long delays, which decreases survivors’ access to vital services and justice. We investigated whether an immediate interview via a mobile phone application (SV_CaseStudy Mobile Application, hereafter MobApp) developed by the Kenyan Survivors of Sexual Violence Network preserves people’s memory accuracy over time. Participants (N = 90) viewed a mock burglary and were then interviewed either immediately using MobApp or MobApp+ (which included additional questions about the offender’s behaviour) and again one week later (n = 60), or solely after a one-week delay (n = 30). We found that memory accuracy one week later was higher for participants immediately interviewed with MobApp or MobApp+ compared to those interviewed solely after a one-week delay. Additionally, memory accuracy was maintained for those interviewed with the mobile application across the one-week period. These findings indicate that the mobile phone application is promising for preserving memory accuracy in contexts where crimes are reported to the police after a delay.