Flutter InAppWebView 
What is flutter_inappwebview? It’s a Flutter plugin that allows you to incorporate WebView widgets into your Flutter app, to use headless WebViews, or to use In-App browsers.
Latest Release: v5.4.2 Null safety
WebView integrated into the widget tree.
Adding the InAppWebView widget into your app is very simple. It’s just a widget like any other Flutter widget: InAppWebView(initialUrlRequest: URLRequest(url: Uri.parse("https://flutter.dev"))).
You can listen to a lot of events and use the InAppWebViewController to control your InAppWebView instances!
Open An In-App Browser.
Use InAppBrowser or ChromeSafariBrowser to open an in-app browser! ChromeSafariBrowser is based on Chrome Custom Tabs on Android and on SFSafariViewController on iOS.
Create a Class that extends the InAppBrowser/ChromeSafariBrowser Class in order to override the callbacks to manage the browser events.
Use Headless WebViews.
It can be used to run a WebView in background without attaching an InAppWebView to the widget tree.
As InAppWebView, it has the same options and events. Use InAppWebViewController to control the headless WebView instance.
