Deep Link

GuestAppViewController.m

/*
Place following code in your info.plist file.

<key>LSApplicationQueriesSchemes</key>
  <array>
    <string>hostApplicationURLScheme</string>
  </array>
*/

#import <StoreKit/StoreKit.h>

static NSString *const kCustomURLString = @"hostApplicationURLScheme://?param1=123abct&param2=abcde";
static NSInteger const kAppIdientifier = <YOUR_APP_ID>;

@interface GuestAppViewController () <SKStoreProductViewControllerDelegate>
  
@implementation GuestAppViewController

- (void)openApp {
    NSURL *customURL = [NSURL URLWithString:kCustomURLString];
    
    if ([[UIApplication sharedApplication] canOpenURL:customURL]) {
        [[UIApplication sharedApplication] openURL:customURL];
    } else {
        [self openAppStore];
    }
}

- (void)openAppStore {
    SKStoreProductViewController *storeViewController = [SKStoreProductViewController new];
    storeViewController.delegate = self;
    
    NSNumber *identifier = [NSNumber numberWithInteger:kAppIdientifier];
    
    NSDictionary *parameters = @{ SKStoreProductParameterITunesItemIdentifier:identifier };
    [storeViewController loadProductWithParameters:parameters
                                   completionBlock:^(BOOL result, NSError *error) {
                                       if (result)
                                           [self presentViewController:storeViewController
                                                                        animated:YES
                                                                      completion:nil];
                                       else {
                                           NSLog(@"SKStoreProductViewController error: %@", error);
                                       }
                                   }];
}

#pragma mark - <SKStoreProductViewControllerDelegate>

- (void)productViewControllerDidFinish:(SKStoreProductViewController *)viewController {
    [viewController dismissViewControllerAnimated:YES completion:nil];
}

@end

HostApplicationAppDelegate.m

/*
Place following code in your info.plist file.

<array>
		<dict>
			<key>CFBundleURLName</key>
			<string>com.hostApplication.bundle</string>
			<key>CFBundleURLSchemes</key>
			<array>
				<string>hostApplicationURLScheme</string>
			</array>
		</dict>
	</array>
*/
  
@implementation HostApplicationAppDelegate

- (BOOL)application:(UIApplication *)app openURL:(NSURL *)url options:(NSDictionary<UIApplicationOpenURLOptionsKey,id> *)options {
    NSLog(@"Source application: %@", options[UIApplicationOpenURLOptionsSourceApplicationKey]); //com.questApp.bundle
    NSLog(@"URL scheme: %@", [url scheme]);  //hostApplicationURLScheme
    NSLog(@"URL query: %@", [url query]); //param1=123&param2=abc
}

@end