Store large number of data in iOS

I am creating an app for existing eCommerce web site like amazon,flipkart, etc,. I am thinking to store some part of information in local storage after the first REST API call to reduce the API calls and save time to show UI faster. I am wondering what could be the best way to store products information in local storage or relay on REST calls? If its local storage which is the best method or approach to handle data effectively and speed in performance?