  When people need help with their day-to-day activities, they turn to family,
friends or neighbours. But despite an increasingly networked world, technology
falls short in finding suitable volunteers. In this paper, we propose uHelp, a
platform for building a community of helpful people and supporting community
members find the appropriate help within their social network. Lately,
applications that focus on finding volunteers have started to appear, such as
Helpin or Facebook's Community Help. However, what distinguishes uHelp from
existing applications is its trust-based intelligent search for volunteers.
Although trust is crucial to these innovative social applications, none of them
have seriously achieved yet a trust-building solution such as that of uHelp.
uHelp's intelligent search for volunteers is based on a number of AI
technologies: (1) a novel trust-based flooding algorithm that navigates one's
social network looking for appropriate trustworthy volunteers; (2) a novel
trust model that maintains the trustworthiness of peers by learning from their
similar past experiences; and (3) a semantic similarity model that assesses the
similarity of experiences. This article presents the uHelp application,
describes the underlying AI technologies that allow uHelp find trustworthy
volunteers efficiently, and illustrates the implementation details. uHelp's
initial prototype has been tested with a community of single parents in
Barcelona, and the app is available online at both Apple Store and Google Play.
