Has it been released yet, outside of the Isle of Wight?
I won't be downloading the government app.
I think test / isolate / trace / quarantine is the only strategy that will get us out of this. It's the only thing that has worked anywhere in the world, with or without various other measures.
Unless we get our heads round this we will be stuck in an increasingly damaging cycle of lockdown - surge - lockdown - surge ... in the hope that we eventually get a vaccine and that when we do we still have enough infrastructure left to deliver an effective vaccine programme.
It's not the economy vs. lockdown. If we don't learn to contain this virus then we can expect several times the current death toll and a fucked economy, as well as many times worse toll on our mental and social wellbeing.
We have to get this right or we are fucked.
Even a good app would only be a helpful additional tool. It relies on people to have a smart phone, download an app, switch it on, switch bluetooth on, take it with them every time they go out ... and the proportion of people who will realistically go through all of these stages is not very big.
We don't even have a good app. Ours has major data protection issues and is not compatible with anyone else's. This might be important for anyone wanting to go abroad in the next few months / years.
Contact tracing overwhelmingly needs to be done by humans, not only because of the shortcomings of any app, but because it's an intrusive and distressing process which will not work in the absence of trust. There are still many things wrong with the way human contact tracing has been set up but that's where we should be focussing our efforts.