To transfer an app to a team, click on the three dots on the app tile and select the team you wish to move the app to.
If you want to keep a copy of the app in your personal account, make sure to
duplicate the app first and then transfer it to your team afterward.
When you move an app to a team, all members will be able to access it and any sheet that it is connected to. The billing for that app will also be migrated to the new team.