The Corona-Warn-App is finally here: This German app is programmed to warn you once you’ve been in contact with a person infected with Covid-19. We’ll tell you how it works and why you do not have to worry about privacy issues.
How does the free Corona-Warn-App work?
The Corona-Warn-App works with tracing functions via Bluetooth. Once a smartphone has the Corona-Warn-App installed and activated, contact tracing is enabled.
If the owner of a smartphone is tested positive for Covid-19, they can register their positive test within the app. The app sends a warning to all Corona-Warn-App users, that have spent more than 15 minutes in proximity to this infected app user. The app does not save any location details or personal data, you just have a random ID. So neither the other app users nor the government knows where this meeting took place or who the respective app users are.
In addition, users should be able to check their Corona-test within the app. This function is not yet available, but planned for the near future.
How to use the Corona-Warn-App
Time needed: 2 minutes.
- Confirm general information and data privacy
Before you can use the app, you will have to read some general information and confirm the Data Privacy Information.
- Enable Covid-19 Exposure Logging
After that, you can enable or disable the Covid-19 Exposure Logging and Notification. Please note, that you have to enable this function otherwise the app will not work properly. You can also allow the app to send you push notifications, to notify you if you were in contact with a person tested positive for the Coronavirus.
- Using the Risk Calculator function
In this part of the app, you can see if you have been in contact with or in proximity to a person that has been tested positive for Covid-19. This information is updated every 24 hours.
- Using the Test Registration feature
Here you can register your own test result, in case you have been tested positive for Covid-19. You can either scan a QR Code or enter a TAN number, which you have received with the letter informing you of your test result.
What to do when the app warns you
Your smartphone will compare all of your Bluetooth contacts of the last 14 days every 24 hours. In case there is a person within these contacts, which was tested positive, you will receive a warning that you may have been in contact with this person. The Corona-Warn-App is only a means of information and will merely inform you about the possibility of an infection.
The app will then recommend further actions you can take, like informing your doctor and health department as well as getting tested for Covid-19. However, none of these measures are mandatory, even though strongly recommended.
What to do if you have been tested positive for Covid-19
If you receive a positive Covid-19 test result, you will receive a letter from the laboratory with a QR Code and a TAN number. You can anonymously register your test result within the app to warn people who have been in contact with you so they can get tested as well. This action is also not mandatory, however, it can help stop the spread of the Coronavirus.
Technical requirements for the app
The Corona-Warn-App works on iOS and Google Android smartphones, it does not yet work on Android phones without Google Play Services, like Huawei phones. At least iOs 13.5 or Android 6 are required for the app to run on your phone.
You also need some other technical requirements:
- Active internet connection
- Bluetooth has to be activated
- Memory space of at least 10 MB
- GPS (for Android users)
- Camera to scan QR Codes (for test registration)
For Android smartphones you will have to keep your Bluetooth activated for the app to work properly. If you have an Apple iPhone with iOS you can deactivate Bluetooth in your control center – the app can still work normally. If you switch off Bluetooth within your settings, the app will not work properly anymore.
Where can you download the app?
At the moment you can only download the free Corona-Warn-App in Germany. Also, if you’re an Android user, your Google Play Store account has to be registered in Germany. However, developers are working on making the download available for users, who are in Germany, even though their accounts are not registered in Germany.

Other countries also use apps and other digital means to help fight the Coronavirus. Austria, Australia and Singapore, like Germany, use tracing as well, while other countries like Iceland, Norway and South Korea use tracking instead.
Data Privacy within the Corona-Warn-App
For the app to be GDPR compliant, a lot of safety measures had to be taken. The GDPR is an important data privacy directive in the EU, which is why the developement of the Corona-Warn-App took some time. Now the app is safe to use under the data privacy directive.
All information the app collects – ID-number of user, Bluetooth contacts and health status – is stored separately and without personal data. Instead of names, the app uses random ID-numbers. This is also the reason, Germany chose a tracing app over a tracking app, as this form of app does not use geographical data of the user, only the proximity of other cell phones with the installed app. You also don’t have to enter any personal data – like your e-mail address or phone number – to use the app.
Corona-Apps in the US
In the US there are several popular apps, some of which are only used in specific states or regions. Also there are a number of Corona apps still in the making.
- North and South Dakota: “Care19” is a contact tracing app that uses data of visits, where the users have spent more than 10 minutes
- Utah: “HealthyTogether” is also a contact tracing app that uses Bluetooth and location tracing to detect potential infection risks
- Another already launched app is “COVID control” by the John Hopkins University
- Apps in the making: “COVID Safe Paths”, “CoEpi” and “Covid Watch”
Corona-Apps all over the world
All over the world, Corona-Apps and systems are being developed to help with the fight against the Coronavirus.
- One of the first apps launched in Australia – “COVIDSafe” has already been downloaded by more than six million Australians. However, the Bluetooth technology seems to not be precise enough between Android and Apple smartphones.
- In Singapure, the app “Trace Together” was launched in June. This app would not be compliant with the privacy and safety standards in Europe though.
- This is also the case for apps in Taiwan, where quarantine is being monitored, and in South Korea and India, where neighbors are being informed if someone tests positive for Covid-19.