App Exposé
App Exposé is a display of all your open windows of a particular app.
To open App Exposé, do any of the following:
Open Exposé and tap an app icon in one of the windows.
Touch and hold an apps icon on the Home Screen, in the Dock, or in App Library, then tap Show All Windows.
In an open app, open the menu bar, tap the Window menu, then choose Show All Windows.
To see more apps, swipe right. To close App Exposé, tap the screen or press the Home button (on an iPad with a Home button).