Simple example of SKStoreReviewController use.

StoreKitExample.swift

func requestUserReview() {
    
    if #available(iOS 10.3, *) {
        
        SKStoreReviewController.requestReview()
        return
        
    }
    
    // Old approach using UIApplication.
    let appIdString = "idXXXXXXXXX" // Your App ID ;)
    let appStoreUrlString = "itms-apps://itunes.apple.com/app/\(appIdString)"
    let appStoreUrl = URL(string: appStoreUrlString)
    
    guard let url = appStoreUrl else {
        
        return
        
    }
    
    if #available(iOS 10.0, *) {
        
        UIApplication.shared.open(url, options: [:], completionHandler: nil)
        
    } else {
        
        // Instance method openURL(_:) is deprecated, use only in older iOS versions.
        UIApplication.shared.openURL(url)
        
    }
    
}