Reading or writing data to and from other app instances is accomplished using the App Connections, found in the Integration section of the Behavior Toolbox. These commands let you get or set data from specific fields in another instance by referencing the other app instance ID. This instance ID can be taken from an app field.
If you are using the Show App Button and its Instance property is set to Single Child, then you can reference this button object and PerfectApps will return the app instance associated with that button.
Return to: Linking Apps and Using Parent-Child Relationships, Designing an App
