Abstract-The objective of this study was to unveil the importance of emotions and feelings in developing mobile-based tourism applications. We gathered and analyzed emotional requirements to develop a mobile context-aware application for tourists. Emotional requirements are non-functional requirements affecting users' emotional experiences around using applications, which are important for sustainable application usage. Many tourism applications exist, but were designed without considering emotional requirements or related UX factors and emotions. We developed a proof-of-concept prototype servicebased context-aware tourism application (SCATA), and users participated in the design and evaluation processes. Emotional requirements are key to sustainable usage, especially regarding security. This paper details the application design and evaluation processes, emotional requirements analysis in each design phase, and the emotional effects of content accessibility in the application's offline mode in unknown environments. The results show that trust, security, adjustability, and reliability are important factors to users, especially in unknown environments.