Hey. Cerbos is much better suited for securing your backend API. If you're looking for an on-device solution, that's a bit tricky because Cerbos is an external authorization solution and needs a way to run the PDP alongside the application.
Cerbos Hub customers do get access to a feature called embedded PDP which a self-contained WASM module generated from your policies. If you're happy to include a WASM runtime in your app, that could be an option.