1. A computer-implemented method for facilitating sharing of content items via an application, the method comprising: receiving data, via one or more processing devices, from a first user of the application for forming a group comprising a group identifier and an associated set of one or more identified users; receiving from the first user, via one or more processing devices, a content item, which is associated with an access identifier; and responsive to a group identifier satisfying an access rule that defines a relationship between the access identifier of the content item and a group identifier and is used to ascertain access rights to the content item by comparing the group identifier with the access identifier according to the access rule, allowing the set of one or more identified users associated with the group identifier access to the content item.