Chronographer

Periodically collect data points, comparing your watch’s indicated time to the current correct time. Chronographer tracks offsets (the difference from the correct time) and daily rate (how many seconds it gains or loses per day). It uses this information to create graphs and histograms that help you visualize your watch’s performance over time. Chronographer also calculates detailed metrics about each watch’s accuracy.

Chronographer can record the watches you wear each day, allowing you to compare wrist time and to see how long it’s been since you’ve worn each of your watches.

Chronographer is completely free. There are no in-app purchases, subscriptions, or ads. There is no “Pro” version.