In this contribution, we investigate the use of mobile technology in e-participation contexts and we define grounds for mobile participation. Mobile participation (mPart) requires the support by tools comprising mobile digital client equipment, mobile access to the Internet, and service support of the related communication. This allows for new types of engagement of citizens in political decision-making at any time wherever citizens physically are. Different participation scenarios require different types of mPart tools. Information gathering, opinion polls, posts to political discussions in social media and in standard e-participation platforms, quick feedback forms, and group and event cooperation are some examples of participation scenarios, which we regard as mPart applications. In this paper, we examine different projects exploiting mobile technology for citizen participation – with a focus on e-participation – and we describe mPart applications and related tools that are developed and evaluated by the authors in a project. The mPart tools are embedded in a layered mPart architecture that allows a flexible integration of tools over an underlying secure communication infrastructure. The architecture serves as a reference architecture for integrating mPart tools.