TL:DR; i-Fun Viewer is fast, image viewer with support for all common image formats.
i-Fu. Other features include: Ability to assign text descriptions to images, Twain Scanner and digital camera support
Ultra File Opener (UFO) recovers photos stored in ITHMB format generated by iPhone, iPad, and iPod Touch. With UFO you can view ITHMB photos, convert them to popular JPEG or PNG file formats, and make beautiful photo prints.
Allow to see the contents of a PDF document without opening it in Windows 10 Explorer. When you're looking for a PDF file or you just need a bit of information from one, to preview PDF documents in a fast preview window is easier than opening files.
View, convert and print graphic files in normal, batch and command line modes. Input formats: DXF, TIF, JPG, JP2, PCX, BMP, DIB, RLE, PNG, WMF, EMF, TGA, VDA, ICB, VST, PIX, PXM, PPM, PGM, ICO, CUR. Output: JPG, TIF, PCX, PNG, BMP, GIF,TGA,WMF,EMF.