Watch Tuner Lite 4+

This app is easy to work. It just requires a little trial and error on the sensitivity slider to find the right balance and get a reading. However, it might not work well on all watches. On my Seiko with a 6R15 movement, it can pick up the ticking from any angle and with the case back still on. However, on my Seiko with a 7S26, the ticking is too soft and the app can’t pick it up with the case back on. Another small thing is that the accuracy is not perfect, it was around +/- 3 seconds when I compared what the app reported vs a 24 hr observation against an official atomic clock. This might be because the measuring time from the app is pretty short. Good enough for practical application though. This app was a game changer for me and allowed me to regulate my watch for a tiny fraction of the cost of getting a timegrapher. I look forward to trying it on a Swiss ETA movement, etc.

This worked exactly as expected. Like reallly really well. It’s obviously not a timegrapher, but if you use as directed you can set a Seiko 7s28 to within +\- 5 seconds/day or better.

I hid in a quiet closet away from my loud kids and opened the caseback, set my iPhone wired earbuds mic on the case, and got a signal no problem. The measurement is way more accurate than your ability to push the 7s28 regulating lever, so it takes a few tries.

I bought this thinking it might be a bust. It was so super good this is the only online review for anything I’ve ever written. If it’s not working for you, you’re not following the directions. The accuracy I have on an SKX007 is (for now) within 2 seconds/day and it feels like a million bucks because of it. Great job!

I was able to get a reading when laying my watch face down on my iPhone near the built-in microphone (in the lower left corner). It didn’t work when laying the watch on its side—not loud enough. This did not allow me to measure my watch in different positions.
I tried using my original AirPods, but that didn’t work at all.
I finally pulled out the wired headphones that came with one of my iPhones. I held the microphone part against the back of the watch with a wire tie wrap. Masking tape should work even better. I set sensitivity = 2/3, noise cancellation = on, and measuring time = long. This produced stable results in most positions. These generally agreed with my seconds/day measurements for 24 hours, but of course is much faster!