Better than I expected it to be. I used it with the headset it said to use, and I was able to get an accurate reading from my ST1901 which I knew was very off at about +13 s/d. I tried to use it with my Navitimer B01 and had a little trouble since it was so quiet and the signal was somewhat noisy, but it still did a decent job and gave me a good readout with very reasonable result. I’m pretty happy with my purchase as I don’t need incredible accuracy, but just want to be able to tell if my Navitimer should ever go in for service early. Thanks!

I just got a used older automatic watch to learn how to work on watches as a hobby. As is, it was running 5 minutes ahead every day. I needed something to adjust it, but didn’t want to spend the $200 or so for the standalone equipment, or even $50’ish for a Chinese knockoff. After watching some “how-to’s” on You Tube, I got this app and got my unopened and almost forgotten Apple earbuds out of the iPhone box. The app picked up a weak signal right away, and had a strong signal after I got the microphone into a good position. It automatically determined my watch settings. As I worked, the graph display immediately told me if I went the wrong way or too far. In 5 or 10 minutes I got the errors down to below 5 seconds a day, mind you, a beginner working on such a small scale for the first time, with the final adjustments essentially too small for me to see. A day later the watch is still running within a few seconds of my iPhone clock. Now I can buy a few more watches to fix up, wear, and keep adjusted, in no small part because of the low cost of this app. Very, very cool… and fun too… Thank you for this app.

I’ve struggled with other apps that are either too sensitive or not sensitive enough and that can take a lot of time to get a useful measurement. Timegrapher solved those problems, and I am more frequently regulating my watches because of its ease of use and the good results I get. It is important to use the microphone on a pair of wired buds. I used small strips of gaffer’s tape to hold the microphone to the back of the watch. The app developer recommends placing it on or next to the crown. Avoid using the phone’s built-in microphone since your results will not be good and since the magnetic field of the phone speakers next to the built in mic could magnetize parts of your movement.

I am quite impressed with this app so far. In a quiet room I was able to get some solid data and improve the accuracy of my Seiko from -7s/d to +3s/d. I’d be really interested to compare date from a standalone time grapher, but alas I do not have access. I also really appreciate that this developer collects zero data, and has one of the best privacy policy’s I’ve ever read. A breath of fresh air