You can use a copy of the sample app by cloning it:
After you clone the sample app, under the tutorial_sample folder there should now be a copy of the sign-in-kotlin sample app folder.
Repeat the steps in the Set up the first mobile app section for the second app.
Replace the URIs with com.second.sample and replace the clientId with the Client ID from the second app that you created in Okta. The Org URL remains the same to share the sign-on session.
Run the second application and attempt to sign in. If the first application's session hasn't expired, you shouldn't be prompted for sign-in credentials.