Effective management of interaction context, user incentivization, and optional privacy controls benefit participatory sensing mobile applications for environmental and health monitoring by improving the quality and quantity of data shared. This work provides a conceptual framework for these challenges and the tradeoffs between: context and resource consumption, context and user effort, privacy and utility, and user incentivization. The expression of these issues is explored through two case study applications--CyanoTracker and PillSafe.Mobile applications for citizen science may automatically consider and capture the context surrounding interaction with citizen science projects. This data may include the time, date, location, weather conditions, and other data useful to the application.Encouraging participation in these projects requires consideration of user motivations as well as the potential incentivization mechanisms. These reward systems must value a report in the context of the application as it relates to the quantity and quality of data received. The burden associated with report submission should evaluated and factored in to the incentivization strategies.Privacy-conscious individuals may be hesitant to participate in citizen science projects which do not provide adequate control over the degree of information sharing. A balance should be struck between preserving privacy and providing high quality data to the project.