In android, you define permissions for gps, sms sending, location , .., in the manifest file. Is there anything similar in the iOS, so the user would know what capabilities
There's no such things as permissions on iPhone.
The only thing that user is warned about is when application uses his current location - then user is prompted with system alert and must explicitly allow or deny application's access to location data.
What concerns sms and email, they can be created and sent only via standard controllers so user will be aware of that anyway