As social media platforms like Twitter and Facebook increasingly shape the way we communicate, new networks, groups and ideas are being formed at a staggering rate. The widespread use of online services triggers new research and application challenges as well as new opportunities. Moreover, the increasing use of social software on mobile devices, from cell phones to mini laptops, also creates a need for the development of new software. Such development relies on various disciplines, especially that of requirements engineering (RE). This discipline involves capturing, structuring, and accurately representing the user's requirements so that they can be correctly embodied in systems which meet them. The 'Contextual requirements elicitation for mobile social software' (Core-mososo) project investigated design factors that are critical to the success of mobile social applications. This EU-funded project was hosted at the Centre for Human Computer Interaction Design at City University in London, UK. It probed new methods and tools that influence the successful planning, development and subsequent utilisation of mobile social software. The output of this project is iRequire, a tool that identifies the requirements for mobile social software, and will soon do so for other applications too. The tool enables system end-users to document their own needs, allowing these to flow into further software development. The tool-supported method considers recent trends in social software including mobility, location awareness and service-centric system design. More specifically, iRequire makes use of context sensing capabilities provided by modern mobile devices (e.g. detection of location). It can identify a wealth of information onsite and can be used to improve such identification and discover requirements. For example, this information can be used to enrich requirements of workshops based on different scenarios, say in a particular field or context, by providing more domain-specific knowledge to participants. Such tools hold promise for the future as they will likely be used in several disciplines. They generally allow users to document needs, something not exclusive to the field of mobile social software. The project team has concentrated in particular on the exploration of the tool's potential for uses in business process reengineering activities. While the example of social media has allowed the team to apply the tool effectively, the relevance of Core-mososo for numerous other business processes and applications is set to be significant.