technical feasability
Does anyone know what went wrong with the first, home-grown app ? I recall that the developers weren't allowed sufficiently low-level access to bluetooth but I don't know what it was like on Android.
I never installed the app (and I haven't yet caught covid, fyi on the correlation/causation thread above). I felt it was technically ludicrous : there was a mild link between covid and bluetooth in the fact that neither work at long distance, but once you get down to the detail, doing anything without either overwhelming false-positives or very poor useful warnings seemed a hopeless task. Perhaps the early developers found this. The article above certainly seems to support it.
Google and Apple, perhaps, had an interest in creating a public health positive for smartphones and avoided the negative side by leaving the statistical choice (time/strength of exposure) to appcode authors and the authorities.
Biting the hand that feeds IT
