More than 64 countries and regions have, so far, developed COVID-19 contact-tracing apps to limit the spread of coronavirus. However, many experts and scientists cast doubt on the effectiveness of those apps. For each app, between a few hundred to a few thousand reviews have been entered by end-users in app stores. In this paper, we mine insights from the user reviews of contact-tracing apps of eight European countries to find out what end users think of COVID contact-tracing apps and the main problems that users have reported. IEEE