In this paper, we present the usability evaluation of IVO (Integrated Virtual Operator), a platform that supports the rapid development of contextaware applications by users with no programming skills. Using only the tools provided by the platform (IVO Builder and IVO Outlook), users can define temporal and spatial conditions and associate them with workflows of activities available within the platform. This way, whenever the defined conditions occur, the user’s smartphone will immediately produce the intended behavior, with no need for user intervention. The applications developed using IVO can easily be made available to other users through a distributed web platform. Moreover, an android client was developed, to run the IVO-developed applications, allowing the smartphone to act as the ubiquitous interaction device. The evaluation of the platform was performed through usability tests at both the end-user level (android client) and the developer-user level (builder tools).