Modern software systems are rarely built from scratch. They rather evolve over a long period of time while components and subsystems are developed independently. During that evolution, new and changing requirements emerge when end-users interact with the system. Users encounter situations that provoke spontaneous complaints or suggestions, which may be the seed of new requirements. However, there are two challenges: How to capture spontaneous reactions and how to focus and let them mature into valid requirements? We propose concepts that enable citizens to report a problem or make a suggestion by Smartphone. A key for preserving the spontaneous impetus is to lower the threshold for composing and sending feedback. Software providers who are interested in feedback can define filtering and focusing aids; they guide end-users in giving focused feedback. Focused feedback is also better prepared to be transformed to requirements. Our ConTexter tool demonstrates technical feasibility of these concepts. We explore and characterize a potential application domain empirically. Based on the findings, we discuss potentials and limitations of our approach.