This is the use case diagram for Small.World.

The Use case diagram below represents the main possible interactions of actors/stakeholders of Small.World. This is inline with the functional requiremnt of the application. The user first need to create account through multiple options such as google+, facebook or create account in Small.World. When the user login they can do different types of activity as shown in the diagram.
The Application, has many options that allows user to do videio conferencing, tag user on map and store past activity log, GPS tracking and pay per click advertisements are some of them.

*Visio Professional by microsoft is used to draw use case diagram because it has significant generralised drawing tools that allows you to produce any diagram very quickly.