Recently, the development of information communication has increased interest in wearable devices and mobile operating systems. Among the various mobile operating systems, Tizen is very popular because of its very easy development environment. Tizen is a multipurpose operating system under development by the Tizen alliance(Samsung, Intel, Huawei, SK, KT, LG U+, etc.) that supports mobile, wearable, and TV. Sony's SmartWatch has a problem in development due to its complicated development process. However, Samsung's Gear S3 provides Tizen Studio and develops native apps based on C and C ++ and web based on HTML, CSS and JS. Therefore, if you have experience of making a web page, you can develop a wearable app with the same concept. In this study, we developed a simple library application that can be used in gear S3, which is a wearable device, so that we can understand the process and the procedure and identify the problems when applied to wearable devices. We have confirmed that Gears S3 apps from Tizen Studio have the advantage of being easy to re-implement easily by customizing the application composed of existing web sites. The function of turning on wrists has interfered with the developed apps and confirmed that the screen turns off.