I dont see how it will actually ease lock down at all.
People could end up self isolating again and again and still not have it. Eapecialky if your work with the public.
Who can afford that? Essential, lots of people would end up in self isolation, back at work a few days and back in isolation again. Lots of people would be in a constant, isolation- back out- isolation loop.
How would a shop survive? Customer comes in and a load of your staff have to isolate?
But then, most customer facing roles don't allow you to have enough phone with you. So you wouldn't know if a customer had it, then you spread it to others.
So the people who come into contact with others more, won't have their phone so its pointless.
The app won't reduce a lockdown. If we all go back to or normal life (or as normal as it can be) loads of people will essentially be in lockdown because of their job.
I am also confused about how easy it to sorrad. Experts claiming only 3-4% of the population have it. In which case, its not that easy to spread. We have weeks before lockdown, cases are still going up, so there are people who have been spreading it before disgnosed, but not as easily as we first thought.
If its not that easily spreadable and you are social distancing, then how is this app particularly helpful?