Here's a tip for iOS app developers and mobile web developers: today I learned that Smart App Banners don't appear in private browsing. I haven't seen this documented anywhere!
Smart App Banners appear above a web page in Safari when the page includes a special HTML element, for example:
<meta name="apple-itunes-app" content="app-id=375380948">
You can tap the banner to download the app from the App Store.
My Safari extension StopTheMadness Pro hides Smart App Banners if its website option "Hide some app banners" is enabled.
This is how I learned that Smart App Banners don't appear in private browsing. I was trying to test the StopTheMadness Pro feature, but I couldn't find any examples on the web, because at the time I was using private browsing!
Smart App Banners are often confused with Universal Links, but they're two different, separate technologies. I've written about Universal Links before. Universal Links do appear in private browsing.
Notice that the OPEN button has a slightly different appearance in the Universal Link. Notice also that the Universal Link doesn't have a close widget to dismiss it. You can't hide Universal Links even if you want to. Not even StopTheMadness Pro can hide Universal Links, unfortunately, because they're not part of the HTML.