If you started creating an app for your team before team members were added, you can move it from your My Yapps dashboard into whichever team it should be a part of.
Find the app you'd like to transfer and click the gear icon in the upper right corner of the app's card.
From the drop-down list, click 'Move Yapp'.
Select the team or personal dashboard you want to move the app to when you see the pop-up.
Your app is now in the selected dashboard.
If you've moved an app to a team and already invited members to it, they'll now have access to this app.