The STAYAWAY COVID application was developed exclusively for the iOS (Apple) and Android (Google) operating systems. The application depends specifically on a recent extension of these operating systems called “Exposure Notifications”. The use of this resource enables digital contact tracing applications, such as the STAYAWAY COVID, to: run without constraints when operating in the background; ii) ensure the interoperability between applications on different operating systems; iii) ensure the interoperability with applications from other EU countries and iv) take advantage of the different improvements introduced at the level of the operating system when using Bluetooth Low Energy.

Unfortunately, only the mobile phones with an Apple iOS version equal to or greater than 13.5, and Google Android equal to or greater than 6.0 can actually support “Exposure Notifications”, which leaves out many serviceable devices.

There is nothing to suggest that Apple and Google will include “Exposure Notifications” in previous versions of their operating systems. Concerning Apple, models that do not support the version 13.5 are older than 2015. And the company has launched 14 new models ever since. As to Google, the situation is different, due to the wide range of manufacturers of devices with Android. Google estimates that over 85% of Android mobile phones support the version 6.0 – and, consequently, the “Exposure Notifications”. However, several models of the Huawei brand were excluded, since they are authorised to neither use Google Play Services nor support “Exhibition Notifications”. However, we have information that this company is currently developing services compatible with those of Google and Apple, which may soon enable STAYAWAY COVID to run on all of Huawei mobile phones.

Currently, Android phones still prevent the efficient execution of digital contact tracing applications. The use of Bluetooth in this operating system requires the activation of the location services (e.g., GPS) – which, despite not being used by STAYAWAY COVID, lead to a significant battery drain. Only Google can overcome this issue. In addition, in order to reduce battery drain, several manufacturers include mechanisms specific to their models that automatically stop running applications that are not active and are running in the background. Although STAYAWAY COVID does not stop working when closed, and it continues to send and receive random identifiers, it does not automatically and daily assess the risk. The app only has access to the server hosted by the Portuguese Mint and Official Printing Office, in order to obtain the necessary information, when the user turns it on.