The newly released Google Chromecast has generated an increasing amount of interest for so called second-screen experiences in the market. Although the technology behind such experiences has existed for a couple of years, end users are now truly starting to grasp the concept and benefits of multi-screen. The company, at which the thesis was performed at, provides a cloud-based messaging solution for Internet connected devices, which enables multi-screen use cases. To increase the amount of supported platforms in the solution, new technologies frequently needs to be integrated. In this thesis I have performed an exploratory research & development project with the aim to integrate the Google Cast technology in this multi-screen solution. The fundamental difference in how the two ecosystems were designed resulted in a companion device framework that acted as a wrapper over the technologies. The framework was implemented on the Android platform together with a set of demo applications. The proposed solution should be seen as a starting point for integrating different multi-screen technologies within a single companion device framework. While combining these technologies, a fundamental difference in the user experience between them became apparent. The Google Cast ecosystem relies on the companion device as the interaction point for the end user, whereas television (TV) applications usually have the main interaction point on the actual TV itself via a dedicated remote control. Having this kind of inconsistency within the same set of applications increases the risk of confusion among end users. Therefore I suggest that development of such multi-screen experiences, that combines these technologies, should strive for a high consistency throughout the whole user experience, independent of platforms and technology.

Today's living room context offers more and more possibilities when it comes to when and how to interact with the television and media content offerings. Buzzwords such as "TV Everywhere" is something that both hardware manufacturers, content providers and television networks are pursuing to great lengths. At the core of such marketing schemes is the availability of platform-independent content consumption. In a Utopian setting, the end-user should never have to worry if he or she is currently using a smart TV, tablet, phone or computer to view a video or photos, play music or play games. Taking the concept even further, the devices should also be able to connect and communicate with each other seamlessly. Having for example a television set (first screen) controlled by a mobile phone (second screen) is commonly referred to as companion device interaction and is what this thesis has investigated. More specifically, a way of discovering and launching a first screen application from a second screen application using the zero configuration discovery protocol named DIAL has been implemented into a cross-platform messaging solution. A case study was conducted to gather data about the system and its context as well as what was needed of the framework in terms of architecture design, use cases and implementation details. A proof of concept application was developed for Android that used the proposed framework, showcasing the ease of use and functionality presented in integrating DIAL into such a solution. Since DIAL is so well-documented, easy to understand and is becoming one of the industry standards among consumer electronic manufacturers in terms of device discovery, I believe it should become a standard for so called zero configuration companion device interactivity.