Launching other installed apps is possible only if the target app supports custom URL schemes. Basically, this allows you to use the "Open Link in Web Browser" interaction, on an action field or otherwise, with an app-specific URL as the parameter - e.g., fb://requests should open the Facebook app if said app is installed.
You can also pass values into the target app if the app supports it. This is achieved by using formula syntax to dynamically generate the "Open Web Browser" parameter. E.g., twitter://user?screen_name={{myfieldname}} should open Twitter to the given user's page. Another example for WhatsApp users is to prepare a message to a recipient number and with a message already prepared with text from a text field. The custom URL below is intended to be used in the parameter field of an action button with "Open Link in We Browser" as the user interaction, with the fields in brackets containing data that the user has entered. This data will then be passed into the WhatsAppmessage when the link is launched as the user presses the action button.
https://wa.me/{{textRecpientNumber}}?text={{message}}
A simple way to test custom URL schemes easily is to simply paste these into your device's web browser – normally, this is enough.
For some reason, custom URL schemes are not always readily advertised by app makers. For this reason, we recommend you also search the web to see if there are any URL schemes supported by your target app. Use a search phrase like "custom URL scheme <target app name here>.”
See also:
Launching Your App from a URL (App Links / Deep Linking)