The research scope of this study focused on free communication mobile applications, and this communication tool is the most common function used in both web and mobile communications. For example, Line APP is a leading free communication platform in both web and mobile applications which is utilized by a large number of users. Line is a proprietary application for instant communications on electronic devices such as smartphones, tablet computers, and personal computers. Line users exchange texts, images, video, and audio and conduct free voice over Internet protocol (VoIP) conversations and video conferences. In October 2014, Line announced that it had attracted 560 million users worldwide with 170 million active user accounts. Consequently, this study uses the case of communication mobile applications to discuss mobile applications customer loyalty. The results of a pretest will verify that the respondent sample frequently uses this communication mobile application and finds it attractive. This characteristic is important because participants must use mobile applications in the communication category.