A couple of people tested some meters and some of them are very off and totally shitty.
The relation price/quality is not worth it.
There is the technique available, for making glucose and ketone meters more accurate, but they don't even bother controlling them.
One of the worst out there is Glucocheck. Also the company's philosophy, which does not hold on court legally.
We are in the process of taking legal steps because of it.
Freestyle Libre is another case.
There were attempts to inform the companies, that their meters and monitors are totally off, but they maybe think, that by stupidity denying any wrongdoing, it will change the outcome.
We are talking about more than 30% difference.
Some of the things interacting so far with both Libre and Glucocheck, giving false readings are - hormonal changes, even in the smallest, GlyNac and Aminoacids.