Sorry if this already been posted but I find this very handy and it works like a dream with no adds or other annoying stuff.
Just write Watch Accuracy Meter on Google App Store and pick the one that looks like the on in the picture attached
So sad it doesn't work with Spring Drive but works like a dream with any other mechanical watch.
Hope you'll enjoy as much as I did
I double checked the results with my watchmaker and it's spot on.
Just follow the quick guide and keep very quiet while doing the measurements

Trimis de pe al meu SM-N975F folosind Tapatalk