Background: Life limiting illnesses (LLI) place an enormous burden on the health system including family caregivers who provide care. Mobile Application can increase resources in palliative care which has the potential to improve the preparedness and quality of life of family caregivers. Purpose: This study was conducted to determine the effectiveness of education through the My Semah mobile application to the preparedness and quality of life of family caregivers who care for patients with LLI at home. Method: This research uses quasy-experimental with pre-test and post-test control group design. The study was conducted in February-April 2020 in the Gamping 1 Puskesmas, Sleman, Yogyakarta. Respondents are family caregivers who treat LLI patients selected by quota sampling technique with 25 experimental groups given education through My Semah for 1 month and 25 people in the control group providing care as usual. Data on preparedness were analyzed using the Paired TTest and Independent Samples T-Test, while on quality of life using the Wilcoxon and Mann-Withney test with a significance of p <0.05. Results: The results of the analysis of posttest differences in preparedness between the control group with mean = 71.20 ± 9.51 and experiments with mean = 162.32 ± 23.11 obtained p = 0.000, which indicates an increase in family caregiver preparedness in the experimental group after the intervention was given education through a mobile application. The results of the analysis of quality of life in all domains in the experimental group compared with the control group obtained a value of p = 0,000, which shows an increase in all domains of quality of life of family caregivers after an educational intervention through the My Semah mobile application. Conclusion: Education through mobile applications is effective in increasing the preparedness and quality of life of family caregivers who provide care for LLI patients.