[Context/Motivation] Crowd-based Requirements Engineering (CrowdRE) promises to overcome limitations of traditional requirements engineering by actively involving a larger number of users. A common theme in CrowdRE research is the development and deployment of online platforms where users can autonomously provide their feedback about software. [Problems] However, current platforms only provide minimal guidance regarding the topics men-tioned in the feedback. Therefore it is difficult to map the feedback to existing requirements and identify gaps. [Principal ideas] To address the problems, we present a systematic process for collecting feedback through a variety of structured questions and an online platform which supports the process. We evaluate the process and the platform in the large-scale interdisciplinary research project SMART-AGE. [Contribution] To our best knowledge, this is the first platform that gathers feedback from a large number of users simultaneously through structured queries. Our contributions include a tailored list of questions for feedback collection, an analysis of the user feedback giving behaviour, a comparison of our feedback quality to other platforms and an evaluation of the user acceptance. Our findings indicate that both the quality and quantity of feedback are high, with variations based on the kind of the questions. Additionally, our platform is well accepted by its users.