WidsMob Viewer is an excellent photo viewing software with super fast speed and excellent experience. There are different viewing mode to check thumbnails, full pictures, slideshows, and even manage the photos.
001 Picture Recovery is a reliable picture recovery tool for users to recover pictures lost due to accidental deleting, formatting, and other unknown reasons from PC, SD card, USB Drive and other storage devices.
All round photo browser support both JPEG and RAW formats. You can access to photos within the same folder within one click, or manage the photos between different folders. Select photos from multiple folders to make a slideshow is not a problem. What is more, you can adjust the various photos effects, batch resize, rename, and even convert photos within the program. It should be the most efficient photo viewer for Mac.