Especially on Archive, but also on Android and other mobile operating systems, mobile apps can have their in-app browsers to circumvent the OS provided wrapper around the system browser.
On iOS, the Safari is the only system browser engine whereas on Android you can have other engines too, so less Android applications have in-app browsers.
Most of those in-app browsers are in social media applications that go to great length to keep their users inside a walled garden.
The site [Wayback/Archive] inAppBrowser.com helps checking how severely information is leaked through the in-app browser as those potentially have a lot of control. TikTok is worst capturing all input including credentials like user names and passwords.
The Wiert Corner - irregular stream of stuff 