Easy to fix..
Don't install the app, then you know with 100% confidence that its a scammer.
I know that the app won't be going onto any of our family devices, reasons include
1. Battery life will suffer - blasting out bluetooth all day long like a canary
2. The government has said that they will keep the data for unspecified reasons.. Err, GDPR logic should also apply.
3. Bluetooth only says a big circle from here, not that the person was within 2 metres of me. If social distancing needs 2M, then why use a 100M technology to do that.
4. It doesn't understand vertical spacing, so if I'm 30 metres up or down compared to someone, it won't be able to tell the difference.
5. IT doesn't see everyone,so those with no mobile / those that don't want to use it, the person that wiped their hands with CV on the same hand rail / door etc 20 minutes ago, etc.
6. Not all problems require a technology solution.
7. This is really about making people feel better about things rather than actually fixing the problem.
Now, given that Bluetooth is 2.4GHZ and that's the same frequency (ish) as a microwave oven, then if they could find a way of boosting the power and providing me with an star trek style anti-bacterial surface wiper device, then I might be prepared to use it as that would be useful.
Some that I've mentioned this idea to suggested that Samsung have already started to do this with their Galaxy Note 7 range, bit its a one-time capability..