Flagged as proprietary by GNOME Software
GNOME Software claims that this app is proprietary:
This is because the appdata declares the license to be:
<project_license>GPL-2.0+ and CC-BY-SA-3.0</project_license>
This situation is described on https://gitlab.gnome.org/GNOME/gnome-software/-/wikis/software-metadata#user-content-how-to-fix-incorrect-licensing-information with more details on https://tecnocode.co.uk/2021/07/05/dont-generally-put-cc-by-sa-in-appdata/.