FastStone Image Viewer
6.8#4 in file viewer software$34.95 one-timeFree planWindows
VisitFastStone Image Viewer may suit Windows users who need to browse, edit, compare, or batch-process images, including camera RAW formats. It may also fit users who want scanner support or a portable version for removable storage.
ViewAnyFile.app suits people who want to view or convert varied file types in a browser, including on phones, tablets, or desktops. Clinical users should note its stated HIPAA certification limitation.