I checked out the app and they want 20.00 a month for the basic which seems pretty expensive. You can try for 2 weeks free
I read all the material and think it counts both the mites and the bees. It says it can even find parts of mites.
You get to use it for free for two weeks. I'm thinking about getting it for the two weeks but as I am not at all technical, I am still thinking about it.
Heidi Faust would be a perfect person to test it out. I know she reads the beekeepers forum. So let's see if she responds.
(I'm prejudice in favor of things made in places like Sweden.)
I am thinking that if a phone camera app can detect mites, then you have too many mites and it is probably too late to save the hive. Most mites are on the underside of the visible bees, and when they are visible or on their backs, it is typically in a very infested hive.
I found the phone app that says it can detect mite issues on frames and it is called BeeScanning. It looks like it is free for the first 2 weeks and then there are paid subscriptions monthly and annually. I have not yet used the app so don't know whether it is effective or not, but it sure would be great if it worked.