TimeTagger is an open-source software tool designed for precise and flexible timestamping of events, particularly useful in scientific experiments and data acquisition systems. It allows users to record and analyze time-correlated signals with high resolution, supporting various hardware setups such as time-to-digital converters and counter devices. TimeTagger provides an intuitive interface and powerful scripting capabilities, enabling researchers to customize their measurement workflows, perform real-time data processing, and streamline the workflow from data collection to analysis. Its modular design and active community support make it a valuable resource for experiments requiring accurate timing information and detailed event characterization.