Background and objectives: Kidney stone disease has become an important worldwide socioeconomic issue. However, metaphylaxis fails due to low compliance rates. Therefore, we developed a mobile app (StoneMD: Kidney Stones) for patients with kidney stones to increase compliance in stone metaphylaxis. Materials and methods: To identify the most appropriate design of the app, we searched through the App Store and the Google Play Store and integrated the clinical recommendations of the European Association of Urology (EAU) and the American Urological Association (AUA). To test the value of this app, a questionnaire was developed in which the patient should answer questions about the drinking behavior and the subjective use of the app in the field of metaphylaxis. Results: StoneMD: Kidney Stones offers the opportunity to calculate the individual risk of a new stone episode. In addition, the app offers several features to raise awareness of lifestyle modification, including hydration as metaphylaxis of urolithiasis, reminder of inserted ureteral stents and document the self-measured urine pH. A total of 49 patients participated in the questionnaire: 89.8% (n = 46) of these patients had a smartphone, 73.9% reported a daily intake of <2.5 l, 76.5% of these patients believe that their drinking behavior is positively influenced by the app, 71.7% stated that the app for relapse prevention is more suitable than traditional information brochures, 56.5% want to continue to use the app. Conclusions: StoneMD: Kidney Stones is the first mobile app for stone metaphylaxis. StoneMD might help to improve patient compliance and might lower the risk of stone formation.