Appsfactory app check: Corona warning app updated for reliable Covid-19 warnings
The Corona warning app has been in the stores for about 2 months now, and has already been downloaded 16 million times. In our first Appsfactory app check, performed directly after release, we assessed the app as positive overall, but considered its navigation and structure as well as the integration of tests critical. In the meantime, we can state that, after some teething problems, both the app’s Android and iOS versions required updates to fix problems. In principle, the app has worked with both operating systems so far. It has always exchanged anonymous codes with other users and complied with the promised data protection guidelines. However, as users sometimes learned of the risk of infection too late, we took a closer look at the code and the way the app functioned after the update.
Corona warning app update: Android implementation
In order to detect potential contact with an infected person, data is regularly synchronised between the app and a server. If the app is not open, this synchronisation is usually performed in the background. To save energy and thus extend the battery life of mobile devices, some smartphone manufacturers restrict these background activities. In consequence, the synchronisation cannot take place, and in the worst-case scenario, a Corona warning may arrive too late or not at all, which would clearly cause the app to fall short in terms of functionality.
Our Android lead developers say: “In general, users can always explicitly enable the running of individual applications in the background in the system settings – but as the problem is known to very few people, this is often not taken into account.” The update to version 1.1.1 of the app explicitly allows Android users to enable background execution. This is now easily accessible within the app (Menu > Settings > Prioritised background activities). It would have been helpful had the developers and the Ministry of Health made users aware of this problem and issued corresponding instructions for action directly upon release. Furthermore, most users are not aware of the additional recommendation to open the app at least once a day.
Corona warning app update: iOS implementation
The iOS version of the app also has its weaknesses. “To detect potential contact with an infected person, data is regularly compared between the app and a server. If the app is not open, this synchronisation is usually performed in the background. However, the background update was not regularly performed in conjunction with the operating system. The problem required fine-tuning with the so-called “scheduler” in the Apple interface’s contact protocol,” explain our iOS lead developers. As the lead developer of Deutsche Telekom also admitted, the app should actually be able to perform the daily data synchronisation even if it is only run in the background.
As in the Android version, it is also necessary to activate the background update in the device settings for WLAN as well as mobile data, as well as to enable it for the Corona warning app. This is possible under the menu item General > Background update. In contrast, the anonymous saving of contacts works continuously and automatically. This means that risk contacts from the last two weeks can also be detected during a later comparison. With the update to version 1.1.2, the problem of background updates is solved, although the iOS operating system 13.6 must be installed on the device as a prerequisite for this. However, if the issue persists, users are recommended to open the app regularly.
Outlook and preliminary conclusions
The developers have confirmed that they are working on further updates to solve these problems, which is necessary, because in addition to the maintenance of the app, the solution created by Telekom and SAP is now also receiving attention at European level. In collaboration with the EU Commission, a cross-national solution is to be developed to enable Europe-wide corona warnings.