nsxiv
Neo Simple X Image Viewer.
TLDR
Open images
$ nsxiv [path/to/file1 path/to/file2 ...]
Open images from directories in image mode
$ nsxiv [path/to/directory1 path/to/directory2 ...]
Search directories recursively for images to view
$ nsxiv -r [path/to/directory1 path/to/directory2 ...]
Quit nsxiv
$ q
Switch to thumbnail mode or open selected image in image mode
$ <Return>
Count images forward in image mode
$ n
Count images backward in image mode
$ p