There have been many large-scale investigations of users' mobile app launch behaviour, but all have been conducted on Android, even though recent reports suggest iPhones account for a third of all smartphones in use. We report on the first large-scale analysis of app usage patterns on iPhones. We conduct a reproduction study with a cohort of over 10,000 jailbroken iPhone users, reproducing several studies previously conducted on Android devices. We find some differences, but also significant similarities: e.g. communications apps are the most used on both platforms; similar patterns are apparent of few apps being very popular but there existing a 'long tail' of many apps used by the population; users show similar patterns of 'micro-usage'; almost identical proportions of people use a unique combination of apps. Such similarities add confidence but also specificity about claims of consistency across smartphones. As well as presenting our findings, we discuss issues involved in reproducing studies across platforms.

This paper demonstrates how useful content can be generated as a by-product of an enjoyable mobile multiplayer game. In EyeSpy, players tag geographic locations with photos or text. By locating the places in which other players' tags were created and 'confirming' them, players earn points for themselves and verify the tags' locations. As a side effect of game-play, EyeSpy produces a collection of recognisable and findable geographic details, in the form of photographs and text tags, that can be repurposed to support navigation tasks. Two user trials of the game successfully produced an archive of geo-located photographs and tags, and in a follow-up experiment we compared performance in a navigation task using photographs from the game, with geo-referenced photos collected from the Flickr website. Our experiences with EyeSpy support reflection upon the design challenges presented by 'human computation' and the production of usable by-products through mobile game-play.

Recent advances in mobile device technology have opened up new possibilities in enhancing the experience of spectators at stadium-based sporting events. In creating novel applications for use in such settings, designers must be aware of the current practices of spectators and of features of the environment at such events that novel applications may seek to exploit. This work forms an early part of the Designing the Augmented Stadium project. Data sets have been collected from spectators, logging the results of Bluetooth scans alongside GPS location. This paper presents an information visualization tool that can be used in the analysis and exploration of this data, to provide insight into the activities of spectators, the relationship between an individual spectator and the crowd as a whole and the suitability of stadium environments for applications based on infrastructure such as mobile ad hoc networks (MANETs) and wireless mesh networking. Various visualization tools are described and example cases are illustrated, using several real-world data sets recorded at football matches.

This paper investigates emergent practices around 'microblogging', changing and sharing status within a social group. We present results from a trial of 'Connecto', a phone based status and location sharing application that allows a group to 'tag' areas and have individuals' locations shared automatically on a mobile phone. In use the system moved beyond being an awareness tool to a way of continuing the ongoing 'story' of conversations within the group. Through sharing status and location the system supported each groups' ongoing repartee - a site for social exchange, enjoyment and friendship.

We introduce a location--based game called Feeding Yoshi that provides an example of seamful design, in which key characteristics of its underlying technologies-the coverage and security characteristics of WiFi-are exposed as a core element of gameplay. Feeding Yoshi is also a long--term, wide--area game, being played over a week between three different cities during an initial user study. The study, drawing on participant diaries and interviews, supported by observation and analysis of system logs, reveals players' reactions to the game. We see the different ways in which they embedded play into the patterns of their daily lives, augmenting existing practices and creating new ones, and observe the impact of varying location on both the ease and feel of play. We identify potential design extensions to Feeding Yoshi and conclude that seamful design provides a route to creating engaging experiences that are well adapted to their underlying technologies.

Video games are of increasing importance, both as a cultural phenomenon and as an application of collaborative technology. In particular, many recent online games feature persistent collaborative virtual environments (CVEs), with complex social organisation and strong social bonds between players. This paper presents a study of 'There', one such game, focusing on how There has been appropriated by its players. In particular we describe how its flexibility has allowed players to develop their own forms of play within the game. Three aspects of There are discussed: first, how the environment supports a range of social activities around objects. Second, how the chat environment is used to produce overlapping chat and how the game itself provides topics for conversation. Lastly, how the 'place' of There is a fluid interaction space that supports safe interactions between strangers. The paper concludes by drawing design lessons concerning the importance of supporting shared online activity, interaction between strangers, and the difficulties of designing for play.

Mobile and wearable computers present input/output prob-lems due to limited screen space and interaction techniques. When mobile, users typically focus their visual attention on navigating their environment - making visually demanding interface designs hard to operate. This paper presents two multimodal interaction techniques designed to overcome these problems and allow truly mobile, 'eyes-free' device use. The first is a 3D audio radial pie menu that uses head gestures for selecting items. An evaluation of a range of different audio designs showed that egocentric sounds re-duced task completion time, perceived annoyance, and al-lowed users to walk closer to their preferred walking speed. The second is a sonically enhanced 2D gesture recognition system for use on a belt-mounted PDA. An evaluation of the system with and without audio feedback showed users' ges-tures were more accurate when dynamically guided by au-dio-feedback. These novel interaction techniques demon-strate effective alternatives to visual-centric interface de-signs on mobile devices.