Mobile location sensing applications (MLSAs) represent an emerging genre of applications that exploit Global Positioning System (GPS) technology and facilitate location-based services. The design of MLSAs must incorporate a tradeoff between information accuracy and energy efficiency because GPS technology and data communications are energy expensive and unaffordable for most MLSA platforms, which are battery-powered and therefore resource-constrained. In this study, we propose a two-layer solution to address the above issue. The solution comprises an Event-based GPS Tracking (EBT) scheme and an Inter-Frame Coding (IFC) scheme for energy efficiency on the MLSA GPS tracking and data communication layers respectively. Using a comprehensive set of evaluations, as well as realistic MLSA traces, we evaluate the proposed solution in terms of power saving, location accuracy, and the data compression ratio. The results demonstrate that our solution can achieve better energy efficiency while preserving good location accuracy in all test cases. Moreover, the scheme is simple, effective, and generalizable to other mobile location sensing applications.