In this research, we implemented a location-based task reminder application for Android-based smartphones and tablets. Compared with the existing works, our application takes full advantage of the ubiquitousWLANinfrastructure to achieve better accuracy in indoor locationing. Furthermore, our application gives users a unified user experience because all the established personal-meaningful locations can be displayed on the Google Maps UI, regardless of the location types. Although the current version requires that indoor locations should be pre-visited by the users, this restriction can be easily lifted by incorporating the proposed operating models—telecom-assisted locationing and social-assisted locationing. With the telecom-assisted locationing operating model, the locationing service can become a value-added service for telecom operators with WLAN infrastructure. Furthermore, our work as a foundation of location-based services can be further extended to be used in many other scenarios which comprise both indoor and outdoor environments. Webelieve that the reminder applicationwe developed can contribute to the promotion of individual well-being. Currently, we are developing a new software version by incorporating the social-assisted operating model to boost the usability of our reminder application. At the same time, we will try to lower the power consumption of executing the reminder application. As described in Sect. 4.3, it is a viable solution to use the built-in accelerometer of the mobile device to detect the movement of users, so the application will do location sensing only when the user is moving. Finally, after the newversion is completed,we will evaluate the usability of our system through the questionnaire on the users.