How do I change how my in-app message appears and closes on the device?

In the no-code in-app editor, click In-app settings in the top bar. These settings apply on iOS and Android Native.

Position on screen: Fullscreen, Top, Center, or Bottom.
Present Animation / Close Animation: None, Fade, Left, Right, Up, or Down. Choose Default to use the motion your app already uses for in-apps.
Animation Duration (MS): 100 to 3000 milliseconds. Leave it empty to keep your app's usual timing.
Swipe to close: any combination of Left, Right, Up, and Down.
Show close button: with position, background, corner radius, icon color, and margin. Unlike the other settings, the close button style is stored with the template and shows on every platform.

Then:

Note: None and Fade currently work on Android. On iOS, the message appears and disappears instantly with these options.