Appsfactory app check: an analysis of Germany’s Corona warning app (Corona-Warn-App)
As of today, the federal government’s new Corona warning app is available for download throughout Germany. As Germany’s leading specialist agency for customer-centric digital transformation, we took a closer look at the app, whose code was disclosed by the developers at Telekom and SAP.
We judge the app to be successful overall. Of course, room for improvement exists, but a large number of valuable improvements by the open source community were taken into account by the developers in recent days, resulting in a significant optimisation of the code.
#CoronaWarnApp for iOS in brief
The implementation of the iOS app convinces in terms of UI, architecture and security. Above all, we endorse the state-of-the-art technologies and tools used, which are very similar to our best practices. We also find the rapidly growing number of automated tests and the optimisation of the code in response to feedback from the community positive. We are critical of the lack of use of dependency injection (an essential pattern for reducing the inter-dependency of objects/classes), which makes long-term maintainability and other architecture decisions problematic.
#CoronaWarnApp for Android in brief
We also judge the Android version of the Corona warning app to be functional and without any major flaws. However, we do find deficits in terms of architecture and structure, especially with regard to the SOLID principle. Moreover, we fail to comprehend why some state-of-the-art and best practices (e.g. dependency injection) were omitted in the development of the Android app. The installation of other compatible tracing frameworks (e.g. Contact Shield Huawei) is also unnecessarily complicated as a result. Although tests have been performed, they lack depth and significance in some cases. In our opinion, the Android app’s inadequate structure makes it unnecessarily complex.
#CoronaWarnApp in brief – UX/UI design
To sum up
We find the app is convincing in terms of data protection and functionality; small architectural weaknesses are unlikely to interrupt the release of the first version. Against the background of the realistic development time of 30-40 days, we also consider the overall cost of 20 million euros estimated by Telekom and SAP to be absolutely inflated. In the light of the fact that important preliminary work had already been performed within the context of the DP-3T project and the core contact tracing functionality is carried out via Apple and Google interfaces, the actual in-house software development efforts are very modest.
Remaining questions which we think require clarification:
- When will users of Huawei devices be able to install the app?
- Will health sector representatives including doctors and health authority employees, hospitals etc. also be able to report confirmed cases of Covid-19 infections in order to reduce the risk of infection? We successfully implemented this type of app for the Contact Tracing Center in the Swiss canton of Aargau.
In the coming days and weeks, it will become clear how many users actually install the Corona warning app and what benefits it will ultimately have.