Chronometer is a free iPhone app designed by Kilian Eisenegger in the Utilities & Tools category. The app assists users in tracking the accuracy of their chronometer watches with ease and precision. Before starting, users are advised to set their watch to atomic time and ensure an internet connection for accurate NTP time retrieval.

Upon launching the app, users wait briefly for the NTP server to synchronize, enabling them to take a picture of their watch dial within the app. By freezing the video feed, the app suggests the tracking time from the NTP server, allowing users to adjust their watch time accordingly for accuracy. Additionally, users can input their current altitude for more precise tracking results.