If you have to time an event or meeting, then stagetimer.io can help. It allows you to create timers and control them from other devices. You can then share a fullscreen timer with presenters and the agenda with participants via link.
stagetimer.io inspired how we think about event-focused tooling and real-world usability. Seeing how stagetimer.io is used in live environments helped shape our approach to building Stage Captions for actual event workflows, not just demos.