Toolwatch - Watch accuracy app 4+

This app is nothing more than a stop watch synced to the atomic clock, and for that reason it’s pretty difficult for this app NOT to work. Im pretty sure everyone getting erratic times aren’t setting the “start” time correctly. For instance, when the second hand on my watch struck 12 and I pressed the button, I had to adjust the ‘start’ time to match what my WATCH read at the moment, not what my phone read. When I hit the button my watch read 12:50 but my phone read 12:51. I needed to adjust the start time by -1 minute so the start time was at 12:50. I could be talking smack though who knows.
One downside for me was having to wait 12 hours for the test to conclude.

This is a great app for timing your watches. It's simple, clean, and very easy to use. My ONLY complaint is that I cannot seem to edit the info of my watches once I've added a watch to the list of those I've timed. So, make sure you get it right the first time if you don't want to go on adding a watch multiple times. Other than that, it's my go-to for fast, simple, and accurate measurement of my timepieces. Definitely recommend this app if you're looking to see how well your watches are performing.

Im not sure if Im just not using this app correctly or if its just not accurate. I have a COSC certified watch and its typically about +4 seconds per day. The first couple of measurements looked ok with a +5 s/d and +7 s/d deviation. I assumed the deviation was due to being worn if a more rough environment. However, after sever other measurements were taken over two weeks, the readings ranged from -29s/d to +77 s/d which is outrageous considering the actual deviation appeared to be significanly less. The app then told me to get my watch serviced. I decided to compare the time to the national atomic clock, and according to that, my watch is approx +2 s/d. So either Im doing something wrong or the app is wrong. Im gonna lean towards the latter. Also, having to make an account is really stupid. I’ll give it another couple of chances to see if it stabilizes or I’ll delete it.