I think the correct tactic is to get proper contact tracing in place. Not to close more things again. The report from the guardian complaining about the amateurish way training was dealt with was to me as a civil servant depressingly familiar. Where's this app?
I would agree that a comprehensive test, trace and isolate system would be a preferable response, rather than closing down parts of the economy again. But I don't think the main issue is the lack on an app (which is really just an add-on). The real problem remains the inability to successfully test enough people who are contracting the virus.
The latest NHS Test and Trace figures show that of 3,953 positive tests in the week ending 19th July, 3,887 (98.3%) had their details passed to the Test and Trace service, of which 3,098 (79.7%) were successfully contacted. Out of that number, 2,435 people (79.9%) provided details of those they had been in contact with, of which 77.9% were reached by the contact tracers and asked to self-isolate (incidentally, this in itself is hardly a stunning success, as apparently 69.0% of close contacts reported to the service were living in the same household as the person who had tested positive!).
So, the NHS Test and Trace service is reaching the contacts of 77.9% of 79.9% of 79.7% of 98.3% of the people who test postive every week. This equates to 48.8%, or less than half.
However, the real problem is that the ONS infection survey for the same week estimates that 19,600 became newly infected with the virus. This compares with the 3.953 positive tests for that week, so we are only finding 20.2% of the cases in the first place.
When you factor that into the above numbers, this means that NHS Test and Trace is only successfully reaching 9.8% of the contacts of people who contract the virus each week. For a £10bn "world beating" system, that is nothing short of a disgrace.
Unfortunately, until and unless these problems are fixed, I think we're going to see more tightening of restrictions as the main policy response to rising numbers of new cases.