Archived on 6/5/2022

NHS track and trace mobile app

NorthernMatt
23 Sep '20

It would appear after a few false starts the NHS track and trace mobile app will launch soon:

Here is the link to the apps supporting website:

clausy
24 Sep '20

I’m going to wait a couple of days to see how the internet network security forums rate it, and if it’s going to (maybe) drain my battery before I install it

This is the official data privacy page

Londondrz
24 Sep '20

Downloaded it, seems to work OK. Can’t say much from the security angle but as for battery, I have a Google Pixel 2 so I don’t have a great battery life anyway.

NorthernMatt
24 Sep '20

They claim a 5% impact on battery life, I already have a smartwatch so I already draining power via bluetooth.

I’m interested as well to see if anyone reports data issues.

NorthernMatt
24 Sep '20

My Pixel 4 has a worse battery life than my old Pixel 2. So I have charging pads all over the place!

Londondrz
24 Sep '20

Wow, I always thought the 2 was the worst for battery life.

Sorry, getting a little off topic.

applespider
24 Sep '20

I’ve installed it this morning so that I can see the impact on my battery/phone. We shall see. Apparently SE23 is a ‘medium’ risk area.

clausy
24 Sep '20

Odd. According to the Imperial College model COVID-19 UK Lewisham is still what I’d describe as low.

Londondrz
24 Sep '20

Whereas where I live in the middle of nowhere, we are medium?

anon5422159
24 Sep '20

I just used the new app to check into a restaurant. Really quick and easy to use. Much better than checking in via pen and paper - and with the added sophistication of Apple’s Bluetooth contact tracking functionality.

applespider
24 Sep '20

It apparently bases it off the start of your postcode but does say that neighbouring local authorities have an impact and I think Southwark is higher.

Londondrz
24 Sep '20

Ah, that’s makes some sort of sense.

willmorgan
24 Sep '20

It’s great that this has finally been released. My company has been doing some work for the main NHS app and we saw a massive spike in onboarding (albeit from people downloading the wrong app!), but if our numbers from this morning are anything to go by, a non-trivial number of people have gone for it!

It would be cool, but perhaps not useful for a pleb like me, if the app was able to display a realtime heatmap of the whole country in terms of risk levels.

ChrisR
24 Sep '20

I loaded it this morning as well, although didn’t see a QR code on display when I went to Aldi in Catford this afternoon!

Does anybody know if we have to keep the app open all the time or can it be closed and as long as we keep bluetooth on it will keep checking in the blackground?

clausy
24 Sep '20

I have a feeling the contact tracing core framework is built into both iOS and Android so I think it’s logging ‘pings’ in the background - the app would translate that into useable data. It would be daft if you had to have it open all the time, even in the background.

Edit: this is pretty good:

The exposure notification system is built into Android and iOS and can only be turned on when it has an app from a government or health service installed. It’s this system that generates the codes linked to phones and interactions with other devices.

It doesn’t explicitly answer your question as far as I can see. Implicitly perhaps.

Edit2: the BBC article also suggests:

Those told to go into self-isolation because of a contact-tracing match will not be able to challenge the decision.
https://www.bbc.co.uk/news/technology-54270334

willmorgan
24 Sep '20

That’s correct, I think. In my travels today I noticed the latest version of iOS has this feature added in its changelog. Probably for the best they implement it on the OS level - I imagine you’re going to get negligble effects on battery life in this way.

anon5422159
24 Sep '20

iOS already maintains a single persistent network connection to Apple’s cloud infrastructure to serve push notifications, so I imagine contact tracing will just piggyback on this, and the bandwidth used will be minimal as it’s just exchanging ids and locations.

The Bluetooth pings will definitely consume a little energy.

The BBC article suggests a battery impact of about 5%

willmorgan
24 Sep '20

Being that I don’t leave the house anymore and my battery doesn’t drop below 70% on any given day due to that, I’d happily pay the battery tax if it meant I could go to the cinema again!

Fishface
25 Sep '20

Haha people worried about battery life rather than their own/other peoples life.

neilw
25 Sep '20

It’s not a ridiculous concern… your phone isn’t going to be much good at tracking if it’s run out of battery!

Older phones can have terrible battery life with Bluetooth on… I wouldn’t be surprised if the reason the new app isn’t compatible with iPhones 6 or older is precisely down to battery concerns.

clausy
25 Sep '20

It’s actually because the apps/APIs need a certain bluetooth version to work. But you’re right - it won’t track anything if it’s run out of battery, and even that is dangerous these days - for some people phones are literally a lifeline at night, or even if they need to pay for something, use a map, or call for help.

I get the point about trivialising the practicality of contact tracing with battery life - the main concern is always about data privacy to be honest. If it’s using the proper Apple/Google APIs then it must be OK right? Or should we get thicker tinfoil hats. Apple are famous for privacy and Google is somewhat notorious for ‘don’t be evil’ and everyone loves the NHS. Still no reason not to be somewhat cautious at least for a few days. It’s been so long coming that by now a day or two doesn’t make any difference. I’d like to see a decent netsec ‘teardown’ of the app. Then of course I use the Facebook app, so why am I being paranoid.

anon5422159
25 Sep '20

2% of my battery usage over the last 24 hours. I can live with that:

Incidentally the DiscourseHub app (which I use to browse these forums) was 45%. I don’t think that’s healthy. It’ll do me a world of good to pass these forums into new hands! :grimacing:

Foresthillnick
26 Sep '20

Our IT director reported massive battery drain after installing the app as in 70% to 15% on his journey home (three trains). I wonder if the drain comes from the amount of contacts you have with other people - if you are sat at home it has no contacts to ping but on trains etc there might be hundreds…

clausy
26 Sep '20

There’s a great Facebook post from the guy who worked on the team that built it: (David Bonsall) - I’ll paste it in here (hope that’s OK) rather than linking to Facebook as some people might not have that.

Last 24 hrs I’ve provided the polite version of the following to C4, ITV,BBC, Radio 5, Sky News, Times Radio, LBC. I thought I’d answer a few frequently asked questions more directly, while our communications officer isn’t watching.

Is it going to steal my data?

  • No its completely private. All your data stays on the phone, if you delete the app, you delete the data. Facebook, on the other hand…

Is it going to track me?

  • No it doesn’t know where you are. Uber, Dominos pizza, google maps, on the other hand…

Is Dominic Cummings…

  • No

Why has it taken so long?

  • It was hard. We tested it, made it better, tested it again, made it better, now it’s ready. And we helped Google develop their system. And we beat most states in America

How many people need to download it to work?

  • Two. If you download it and I download it and I get infected and I notify you and you don’t visit your gran, Granny lives

What happens if we all download it?

  • Maths shows it could stop the epidemic.

But Dominic Cummings…

  • Just no

Why did the Isle of Wight app not work?

  • Actually it did. It looks like it stopped their epidemic. There were problems with iPhones.

Are there not still problems with iPhones

  • Yes. The few people with iphones earlier than 6S should write Apple and complain. If you have a later version you should download the app, stop the epidemic, and save the old folks with outdated smartphones.

What about the fines for not following the notifications? Those aren’t fair!

  • What about the local outbreak and deaths you could cause by not following them? also what about the £500 you receive if you get notified and can’t work from home?

Yeah but “False Positives”…

  • The only way you can get a notification is by being close to someone who tests positive for COVID-19 for a prolonged period.

Yeah but its not 100% accurate at measuring distance so there are false positives

  • Do you think the virus cares if it’s 2 meters or 2.3 meters?

Yeah but…

-If I asked you to remember all your 2meter 15minute contacts in the last 3 days would you give me an accurate answer? Where’s your tape measure and your stop watch?

So is it more accurate than manual contact tracing?

-Yes probably. And it can notify people you don’t know.

How else is it better?

  • well it’s a lot more private - you don’t need to give personal details about you or anyone else

Anything else?

  • it uses computers so it’s fast enough to find people BEFORE they infect others…which is sort of the point.

Anything else?

  • it doesn’t require millions of netflix subscriptions.

Anything else?

  • It’s a quick way to check in to bars (I like bars) and it’s a faster way to book a test without navigating a website designed by a Vogon

There are no tests?

  • Fair point. Not my department. But will keep the pressure on.

Its not a silver bullet is it? It’s just a cherry on the cake?

  • No. If we all download it, it’s A GOLD-PLATED MISSILE, which relatively speaking cost one-thousandth of a cherries worth of cake, compared to another lockdown.

Is it going to work?

  • not unless you download it…give it a go. It’s really rather good.

(And well done to our group at Oxford, Alan Turing Institute, department of health, NHSX, Google, Pivotal, Zuhlke, and beyond who’ve all contributed…it’s been a long time coming…and it’s something to be proud of. Well done!)

anon5422159
26 Sep '20

What a dude! That’s a brilliant interview

Londondrz
26 Sep '20

Superb article, thanks @clausy

clausy
26 Sep '20

Yeah I love the conversational style - really fun to read.

Londondrz
26 Sep '20

Will copy and paste (with a credit of course) on another site I am on where a lot are convinced they will be tracked by satellite and dark men in black cars.:sunglasses:

Foresthillnick
26 Sep '20

I have just seen that our school, following Gov advice, has not recommended the apps use in school.
It is not available for under 16s anyway and it is feared that there would be too many false positives due to phones being left unattended for long periods, which is what happens in schools! Of course it is early days and we are watching how it gets used and how things evolve…
Staff are free to use it of course but they must make an effort to have the device on them at all times.

ChrisR
26 Sep '20

Would it also depend on how many of those contacts have downloaded the app?

applespider
26 Sep '20

There’s also a bit about how strong the network signal is on the journey.

There are some journeys where I seem to go through a high amount of battery in a short time - and those are the ones where the signal strength is poor. And other days while I’m still out and about where it barely drops despite using it similarly (both pre-app)

I’m considering moving away from 3 now that I’m out of contract as it seems to eat battery. While in Rome last year, I was using my phone a lot (photos, translations, maps, calls) on a roaming network and my battery didn’t drop below 70% before getting back to the apartment at 6pm. Translate that to a day in London the following week where I wasn’t using it as much - down to 45% at the same time. Only immediately obvious difference is the network.

Rosered
28 Sep '20

So even if you have installed iOS 13.7 you can’t use this on a first gen iPhone SE? Why is it always assumed we all change our phones all the time!

clausy
28 Sep '20

Well I still have my original iPhone and it still powers up, although the battery lasts 5 minutes. The ‘old’ SE’s were great. The issue is with the Bluetooth version - something to do with distance calculations and signal power to measure distance as accurately as possible. Imagine you’re on a train carriage and your bluetooth signal goes 50ft and you’re 50ft away from someone, - you wouldn’t then want to be notified that you were ‘close’ to that someone if your phones handshake and it knows you’re nearby but doesn’t know it was actually 50ft. If they then get a positive result in a couple of days time. It has to be fairly certain you were 2m apart for 15 mins and it somehow does fancy magic with the latest version. Look at it as a case of it works well for 90% of people (who even have a smart phone) instead of badly for 100%.

Brett
30 Sep '20

You can use it on an (original) iPhone SE and am doing so. It is internally the same as a 6S.