Will not run. Gives the following error: GLib-GIO-ERROR **: 14:22:31.397: Settings schema 'org.cinnamon.desktop.interface' is not installed. QGIS died on signal 5.
QGIS is great FoSS and I've had issues installing it on Mint 19.2 Cinnamon until I found this Flatpak. I was able to install it and run it smoothly.
QGIS is rock solid Open Source GIS software suite for most would-be GIS-minded people. It's FOSS, and this FlatPack version of it makes it relatively painless to keep it up-to-date, compared to having to constantly update the repo link every time a new version comes out.
Good option for installing QGIS as the Flatpak includes other libraries necessary to run QGIS. This version (3.4.4) is more up-to-date, too, than the QGIS 2.18 version in the typical repository.