My work explores how smartphones can advance social science research by capturing communication, experiences, and behavior as they unfold in everyday life. I combine mobile surveys and experience sampling with digital behavioral data to study the dynamics of media use, emotions, and political communication. I also help develop research infrastructure, including the GESIS AppKit and tools for mobile tracking. A central aim is to connect rich behavioral data with people’s subjective experiences while protecting privacy through approaches such as local data processing on participants’ devices.