Mobile applications are becoming increasingly datacentric - often relying on cloud services to store, share, and analyze data. App developers have to frequently manage the local storage on the device (e.g., SQLite databases and file systems), as well as data synchronization with cloud services. Developers have to address common issues such as data packaging, handling network failures, supporting disconnected operations, propagating changes, and detecting and resolving conflicts. To free mobile developers from this burden, the authors are building Simba, a platform to rapidly develop and deploy datacentric mobile apps. Simba provides a unified storage and synchronization API for both structured data and unstructured objects.