Incompatibility with the App Immuni

[OlafRadicke]

Describe the bug

I've runned your App for some days and everything was fine. Than I installed the Add "Immuni" (https://play.google.com/store/apps/details?id=it.ministerodellasalute.immuni). On the first look it was fine too, but one day later I opened the corona-warn-app and I saw that tracking has stopped. I've seen the message: Corona-Warn-App does not track your location and doesn't have the permission to do this. So I switched this on again. But now, I get the same warning from the other App "Immuni". With other words: only one of this Apps can run.

Steps to reproduce the issue

• Install and start corona-warn-app
• Install "Immuni" (https://play.google.com/store/apps/details?id=it.ministerodellasalute.immuni).
• wait 10 minutes
• Reopen corona-warn-app and you will see, that is stopped.
• Reactivate corona-warn-app
• Switch back to "Immuni" and see the warning and that the App is stopped now

Technical details

• Mobile device: Nokia 7 plus
• Android version: 10

Additional context

• It's not rooted device
• All Apps are downloadned from Playstore

[mh-]

This is a limitation introduced by Apple and Google - only 1 app can connect to their Exposure Notifications API on each device. I believe they do this to keep complexity for their interfaces low.
Also they have limited the rate how often an app can access the API, for user privacy reasons; and two apps sharing this limit wouldn't work, while doubling the limit for two apps could circumvent the restrictions.

You could however switch between apps (e.g. when you go on vacation in Italy), and they will access the same collected data on the device, just not both apps in parallel. So be careful, Immuni will only tell you about warnings by Italian users, and Corona-Warn-App will only tell you about warnings by German users.

[OlafRadicke]

This is a limitation introduced by Apple and Google - only 1 app can connect to their Exposure Notifications API on each device. I believe they do this to keep complexity for their interfaces low.
Also they have limited the rate how often an app can access the API, for user privacy reasons; and two apps sharing this limit wouldn't work, while doubling the limit for two apps could circumvent the restrictions.

You could however switch between apps (e.g. when you go on vacation in Italy), and they will access the same collected data on the device, just not both apps in parallel. So be careful, Immuni will only tell you about warnings by Italian users, and Corona-Warn-App will only tell you about warnings by German users.

Okay, but then you have a blind spot of three weeks after your Italy vacation. So you have to make a decision. Do you protect your Italian hosts or your German friends and family Who are you going to sacrifice?

[mh-]

I think that if you were tested positive, you could use both apps to upload your TEKs, one after the other. For Corona-Warn-App you need to obtain a teleTAN, for Immuni, I don't know how they check that you have been tested positive.

[OlafRadicke]

I think that if you were tested positive, you could use both apps to upload your TEKs, one after the other. For Corona-Warn-App you need to obtain a teleTAN, for Immuni, I don't know how they check that you have been tested positive.

Okay, if you turn off the Immuni App in Germany, do you still get information about critical contacts in Italy? I think not. If access to the device is exclusive. Then it might make sense to build an API gateway for the notifications to and from Italy (and all other countries).

[OlafRadicke]

Addendum: With Immuni you must be in Italy to upload your code to indicate a positive test. But you will certainly not want to go back to Italy if you are dead sick. Just to upload your code.

I see no alternative to API gateways.

[rampage64]

What's the deal of this issue? why would you want to use both at the same time if you live in Germany?
I hope this discussion is not leading to have several apps for each country.. where as the apps can't live together in one single device, because in Germany there aren't only Germans but Italians as well 🤔.
But in the other point you are right, there should be an list of apps which Corona App can not live together with, like "Immuni" because of Exposure notification API.. Simple users doesn't understand this, they need an info at least 😊

[OlafRadicke]

What's the deal of this issue? why would you want to use both at the same time if you live in Germany?
I hope this discussion is not leading to have several apps for each country.. where as the apps can't live together in one single device, because in Germany there aren't only Germans but Italians as well thinking.
But in the other point you are right, there should be an list of apps which Corona App can not live together with, like "Immuni" because of Exposure notification API.. Simple users doesn't understand this, they need an info at least blush

Oh, remember Ischgl! Hundreds of Germans spent their holidays there and brought the virus home. Next winter - same game. What help does the app offer if the problem is not solved? Right, none.

[MikeJayDee]

At the moment, you can install both and then activate them alternatingly manually every day or so to receive warnings from both apps.

However, it has been communicated that work is underway so that the backends of the apps using GAEN will exchange keys somehow.

[rampage64]

@OlafRadicke Agree the App does not solve the 'corona' or any sickness problem because it's an health problem, but it at least help if used properly to 'slow down' the infection in order that the hospitals will not be overloaded. But with the app the real problem is not Solved!

[tkowark]

Thanks for bringing up these points. That's also more a general issue not only focused on the Android App. Hence, I'll move the issue to the documentation repo.

[jurkov]

A workaround would be to use two different phones. It's not great to carry always two phones, but it's the safest way.

[sventuerpe]

Is everyone aware of the recently released European interoperability guidelines? Would they solve this problem?

[sventuerpe]

To answer my own question in abstract terms after skimming the documents: Once this interoperability solution is implemented, everyone uses the app of their home country with its respective back-end. National apps are extended so that they can register travel to other participating countries, e.g., based on user input. Diagnosis keys are exchanged between national back-ends so that contacts can be properly notified in cross-border situations.

(Please correct me if I misunderstood anything.)

[SebastianWolf-SAP]

Dear colleagues,

sorry for the late answer! It seems that the relevant information has already been shared, thanks to @mh- and @sventuerpe! Cross-border interoperability will be worked on - please follow-up with issue https://github.com/corona-warn-app/cwa-backlog/issues/14. The idea is that you will only need to install one app - the one from your "home" country and the diagnosis keys will be exchanged across the respective backends. Many details will still need to be found out, but as the "Highlander Principle" is forced by the Google/Apple framework, we can't solve this issue.

Mit freundlichen Grüßen/Best regards,
SW
Corona Warn-App Open Source Team