In this section, we briefly review the state of the art and the
related work that has informed our design. We first review
existing mobile social network applications (Section 2.1) and
indicate how Friendlee differs from these. Although Friendlee has
a number of different features, it is the sharing of context
information that has received the most attention in related work.
We review the literature on contextual cues in Section 2.2 and the
associated privacy and sharing rules in Section 2.3.