An exemplary system includes an application portal providing access to items of a plurality of remote applications, wherein at least one of the items is related to more than one of the remote applications, and an authorization layer that is included in the portal and that includes a permission map indicating an association between a user and at least one of the items of the plurality of remote applications that the user is permitted to access. In certain embodiments, the items include an application program interface (API). In certain embodiments, the authorization layer is synchronized with the remote applications, whereby the permission map is updated concerning information about at least one of the items that the user is permitted to access. Corresponding methods and systems are also disclosed.