App development is always more fun and faster in teams! Which is why we've provided you the ability to collaborate with others on apps.
There are two ways to add a teammate:
Bottom left of the left side panel in the app-view.
Settings Page > Team
In addition to adding a teammate, you may also want to remove a teammate. To do so, navigate to the Settings Page > Team, click on the bubble under Teammates that designates the user you wish to remove from this app, and a dropdown will appear that will allow you to remove that user.