Corona-Warn-App

Corona-Warn-App is a COVID-19 contact tracing app used for digital contact tracing in Germany. Despite early discussions over privacy and data security, it had been downloaded by 22.8 million persons as of 19 November 2020.[2] Experts believe that time saved by using the app can be critical for improving the effectiveness contact tracing efforts.[3]

Corona-Warn-App

Screenshot of the Android version, displaying a "low risk" assessment alongside guidance about prevention measures such as hand-washing
Developer(s)	SAP, Deutsche Telekom
Initial release	16 June 2020 (2020-06-16)
Stable release(s)
Android 1.11.0 / 28 January 2021 (2021-01-28) iOS 1.11.0 / 28 January 2021 (2021-01-28)
Repository	github.com/corona-warn-app
Operating system	Android and iOS
Available in	German, English, Turkish, Arabic, Polish, Bulgarian, Romanian, Russian[1]
Type	COVID-19 app
Licence	Apache License
Website	www.coronawarn.app

Use of the app is voluntary and the government says the app complies with Germany's strict privacy laws. The official app works with the Exposure Notification Framework (what is implemented in Google Play Services for Android and in iOS) by using Bluetooth to exchange codes with app users that are within 1.5 meters of each other for a period of at least 10 minutes. An unofficial Corona-Warn-App has been released on F-Droid,[4] making the app available without proprietary components on Android phones.[5]

Anyone who tests positive for COVID-19 can share this information voluntarily with the app. Other app users are then notified about when, how long and at what distance they had contact with the infected person within a 14-day period. Testing is available for users on a voluntary basis. Employers can require that Corona-Warn be installed on company phones, but can not compel its use on private phones.[6]

The open source app, which cost €20 million to develop and is open-source,[7] but relies on the proprietary exposure API, is intended to supplement human contact tracing efforts which Germany put in place in February, during the early stages of the COVID-19 pandemic in Germany. Some Virologists say when at least 60% of people in Germany use it, it would be very effective.[8] The effort has been supported by billboard and broadcast advertisements in cooperation with the German Football Association (DFB) and prominent companies.[3]

At its start the app only worked in Germany, and Jens Spahn, Federal Minister of Health, has said the development of a Europe-wide system is a future goal.[3] With the update published on 19 October 2020 the app supports key-exchanges with the EU Interoperability Gateway and is therefore able to communicate with contact tracing apps from Ireland and Italy.[9] Until now Denmark, Czech Republic, Croatia, Latvia, Poland and Spain join the gateway and are also able to exchange keys with Corona-Warn-App.[10]