I know that it has worked successfully in other countries, but I suspect the mindset of the British public may be quite different to that of the population of say South Korea.
If you were to be identified as a contact of covid-19, would you then self isolate for 14 days if that's what you were told to do?
As an aside, I wonder whether family members would also be told to self isolate?
Anyway:
Yes - I would adhere to the guidance and self isolate for 14 days if either the app or a contact tracer told me I may have been in contact with someone with covid-19 (you would not leave the house for any reason)
No - I would not adhere to that guidance