  We present FedKit, a federated learning (FL) system tailored for
cross-platform FL research on Android and iOS devices. FedKit pipelines
cross-platform FL development by enabling model conversion,
hardware-accelerated training, and cross-platform model aggregation. Our FL
workflow supports flexible machine learning operations (MLOps) in production,
facilitating continuous model delivery and training. We have deployed FedKit in
a real-world use case for health data analysis on university campuses,
demonstrating its effectiveness. FedKit is open-source at
https://github.com/FedCampus/FedKit.
