Android/iOS: How to launch an application from inside another application

Hi all. I'm working on integrating our company's applications for android/iOS to feel more organic and connected to each other. That being said, what I'm trying to do is write a function that checks if another specific application is installed and either launches it if it is or brings the user to the App Store / Google Play page to download that app. Is there any way to achieve this with Application.OpenURL or something similair?

Functionality I'm trying to implement:

-Is the companion app already installed on this device?

-Launch app.

-Navigate to App Store / Google Play page.