ImgControl packaged with pyinstaller.
To run it, download either the windows or linux zip file from the assets below, extract it wherever you want to, and use the executable from there.
(You can use the testImages directory for a quick test.)
Note: the Linux and Windows versions are identical, except the icons of the left/right buttons on the UI bar, and some height changes in the Settings/Help/About sections. These caused a lot of problems in Linux, when testing, both in WSL, and under a full Ubuntu install. (I have no idea why PyQt works differently in the two operating systems...)
Regardless, these are only minor things, and the functionality should be exactly the same.