Determining Trustworthiness and Quality of Mobile Applications Ilung Pranata, Rukshan Athauda, and Geoff Skinner School of Design, Communication and IT University of Newcastle, Australia University Drive, Callaghan, NSW 2300, Australia. {Ilung.Pranata,Rukshan.Athauda,Geoff.Skinner}@newcastle.edu.au Abstract. The growth of “smart” mobile devices, such as smartphones and tablets, has been exponential over the past few years. Such growth was mainly attributed to the development of mobile applications. To date, mobile applications have been increasingly used to improve our productivity and also to provide the entertainment contents. However, with a huge number of mobile applications that appear in the application stores; in particular those that provide similar functionalities, users are often confused with the selection of trustworthy and high quality mobile applications. At the current state, there is a limited research embarked to provide solutions for measuring the trustworthiness of mobile applications prior to download. Thus, the aims of this paper are to review the current research in this area and to discuss several issues in measuring the trustworthiness of mobile applications. In addition, this paper also proposes MobilTrust, a similarity trust measurement method to solve the identified issues. Keywords: trust, reputation, mobile application 1 Introduction The proliferation of mobile computing technology has gained a significant momentum since its first introduction in the 70s. This can be seen from its growth rate that has rocketed over the years. According to the International Telecommunication Union (ITU), the subscribers of mobile devices have surpassed 5.3 billion in 2010 [1] while the total world population in the same year was just about 6.8 billion [2]. Such figures show that in 2010 alone, the percentage of mobile device subscribers is accounted for more than 75% of the world population. In the past few years, “smart” mobile devices such as smartphones and tablets have dominated the growth of mobile devices. An independent research firm IDC [3] published a study that shows the growth of “smart” mobile devices will reach 659.8 million in 2012, up to 33% from the previous year. Furthermore, IDC also forecasted that such growth will remain double digit in the years to come. This is mainly due to the strong user demand and also the production shift from the traditional mobile devices to the new era of “smart” mobile devices. Therefore, it is evident that “smart” mobile devices such as smartphones and tablets have and will continue to become part of our everyday life.