We propose a new tool in the battle to allow smartphone users to control their digital identities: objective-based context mocking. In contrast to privacy-based approaches that try to limit application access to data, mocking allows users to manipulate data-driven impressions of their behavior in well-defined ways, to appear more fit, more social, or more on-time than they actually are. We describe the design of the PocketMocker system which uses user-initiated context trace collection and white-hat data analytics running on the phone to provide control over the mocking process. We also present data from a survey indicating that many users would feel comfortable using our system.