Google App Engine & Google Storage
Since you created the API console project with an Apps account (one @yourdomain.com), the project is automatically treated as an Apps project, and only users from your domain can be added to it.
To avoid this, create a new project using a @gmail.com account, and then add all the developers you want to have access to it. You can then remove the @gmail.com account.
I try to enable Cloud Storage for my GAE app. I read in the docs that:

Add the service account as a project editor to the Google APIs Console
  project that the bucket belongs to. For information about permissions
  in Cloud Storage, see Scopes and Permissions on the Cloud Storage
  documentation.

However when I try to the service account to Team Members at the API Console I get the following message:
User *@*.gserviceaccount.com may not be added to Project "**". Only members from domain *.com may be added.
Any ideas?