You can use the Unity Profiler to profile your application in the Unity Editor to understand how your application will perform. However, due to hardware differences between a desktop development machine and a mobile device, it’s recommended that you profile your application on the device you are developing it for. There are also mobile-specific performance characteristics that can only be profiled on a device, such as the application’s effect on battery life.
For information on how to connect Unity to an instance of your application running on an iOS device, refer to Profile your application on a target platform.