Apps similar to ImgV64 include IrfanView, which is free for personal use. Other options are qView, XnView Classic, Gwenview and JPEGView. Image Viewers like ImgV64 are a crowded field, with more than 25 alternatives for Windows, Linux, Mac, iPhone and iPad.
Gimmage is a small gtk image viewer, perfect for command line usage as it accepts directories and image filenames as arguments. It also has a filechooser integrated into the main UI, making accessing images and directories a snap.
GImageView is a yet another image viewer which solves hopless situation under displaying a lot of images. It provides not only viewing image function but also managing image files function which looks like expolore of MS-Windows or tabbed web browser.
