Sensor data shared for receiving personalized services from mobile applications, embed in them information, which when stitched together can reveal behavioral patterns and possible sensitive inferences, raising serious privacy concerns. In this talk, we will present the information theoretic metrics for privacy and utility and ways of finding the desired level of data obfuscation to satisfy the defined metrics. We will then describe the design and implementation of a context-aware privacy preserving framework on a mobile platform. Specifically, we will focus on the android-based platform changes. The framework learns a behavioral model of the user and uses it to derive the obfuscation function and the extent to which it should be applied to satisfy the privacy and utility metrics.