Sharing an app with another person

ios
fabric
safari

#1

Hello,
I don’t get how to invite another developer to my app?
I have created an app via web browser.
I want to add extra administrator to that app. How can I do that?
My app will be used by iOS, I think I could do something similar by Fabric.
But in my case there is a twitter app that was created earlier, than Fabric appeared, how can I add another developer to that app?