This app is a text message to a number of guardians who have been registered when they do not use their mobile phones for at least 6 hours, such as senior citizens over 65 years of age, disabled people, dementia patients, severely ill patients, and single-person households, kindergarteners, elementary, middle and high school students. It is a relief service developed to prevent damage by sending warnings (sounds, vibrations, etc.) and to enable quick relief in case of danger due to lonely death, disappearance, kidnapping, or inconvenience.It is operated by mobile phone without having a separate server, and since it does not contain personal information, anyone can use it without risk of leakage of personal information.The app will not work if your phone is turned off. Always check your phones battery and charge it.