5.1.extra (my edit)
adds drag and drop, but doesn't select file and crashes on non-image files.
Version 5.3 of the official is out, which adds the Folder Select to menu and fixes the messed up scaling and other issues in 5.2, but doesn't have Drag and Drop added yet.
https://github.com/GarlicCookie/PNG-SD-Info-Viewer/releases