Past years have witnessed the rapid growth of computer-based social software. Despite the increasing popularity of mobile devices, the choices of social software on these devices are still limited to non-real-time email and social media systems. Real-time social software on mobile devices is virtually non-existent due to the device characteristics such as small screen real estate, limited battery talk time, scarce network resources, and inherent need for personalization, which present challenges to the design and implementation of effective and useful real-time mobile social software. In this article, we present a technical solution to these challenges using a smartphone-based real-time collaborative note-taking system as an example. The solution allows for personalized multi-user view through flexible layout of multiple windows, maximally utilizing the available screen real estate, personalized content synchronization through synchronization protocols and algorithms based on the operational transformation technique and a buffer compression algorithm based on the operational merging technique, maximally utilizing the available battery talk time and network resources, and personalized content retrieval through customizable search methods.