Table 1. Outline of the examined apps.
| App’s name | Country | Analysed version | GAEN | Open-source |
|---|---|---|---|---|
| Stopp Corona [15] | Austria | 2.0.8.1133 | ✓ | ✓ |
| Coronalert [16] | Belgium | 1.11.2 | ✓ | ✓ |
| ViruSafe [17] | Bulgaria | 1.0.3 | ✗‡ | ✓ |
| Stop COVID-19 [18] | Croatia | 2.2.0 | ✓ | ✓ |
| CovTracer [19] | Cyprus | 1.3.2 | ✓† | ✓ |
| eRouska [20] | Czech Republic | 2.2.687 | ✓* | ✓ |
| Smittestop [21] | Denmark | 2.1.1 | ✓ | ✗ |
| Hoia [22] | Estonia | 1.0.8 | ✓ | ✗ |
| Koronavilkku [23] | Finland | 2.0.2 | ✓ | ✓ |
| TousAntiCovid [24] | France | 2.2.3 | ✗‡ | ✗ |
| Corona-Warn-App [25] | Germany | 1.10.1 | ✓ | ✓ |
| VirusRadar [26] | Hungary | 1.0.0 | ✗‡ | ✗ |
| COVID Tracker [27] | Ireland | 1.0.4 | ✓ | ✓ |
| Immuni [28] | Italy | 2.2.1 | ✓ | ✓ |
| Apturi Covid [29] | Latvia | 1.1 | ✓ | ✓ |
| Korona Stop LT [30] | Lithuania | 1.1.1 | ✓ | ✗ |
| COVID Alert [31] | Malta | 1.3.5 | ✓ | ✓ |
| CoronaMelder [32] | Netherlands | 1.2.2 | ✓ | ✓ |
| Smittestopp [33] | Norway | 1.0.3 | ✓ | ✓ |
| STOP COVID—ProteGO Safe [34] | Poland | 4.9.0 | ✓ | ✓ |
| STAYAWAY COVID [35] | Portugal | 1.1.2 | ✓ | ✓ |
| ZostanZdravy [36] | Slovakia | 1.1.0 | ✗‡# | ✓ |
| #OstaniZdrav [37] | Slovenia | 1.10.1 | ✓ | ✗ |
| Radar COVID [38] | Spain | 1.2.0 | ✓ | ✓ |
| SwissCovid [39] | Switzerland | 1.3.1 | ✓ | ✓ |
| NHS COVID-19 [40] | UK | 4.3 | ✓ | ✓ |
The interested reader can also refer to [4], which gathers all GAEN-based apps worldwide.
‡Centralised/proprietary approach.
†Formerly known as CovTracer. It embraced GAEN on Dec. 2020.
*From ver. 2.0 onward. Prior versions were based on a centralised framework.
#The official website at https://korona.gov.sk/en/ provides a dead link to Google Play Store.