i hope how to download related two apps,
we make image two apps A and B, such as.
if app A only installed, app A atracts app B from the app store.
did you know how to that?
download related two apps
App B creates a schema and App A executes a canOpenURL
https://developer.apple.com/documentation/uikit/uiapplication/1622952-canopenurl?language=objc
to detect whether App B is on the device. If it is not there you show a screen indicating App B is missing and ask the user if they want to go to the App Store to download it. If they do then you do a
[[UIApplication sharedApplication]
openURL:[NSURL URLWithString:@"https://itunes.apple.com/app/idYOURIDHERE?"] options:@{} completionHandler:nil];