CD Display is one of the most commonly know comic book reader nowadays, its very simple to use and its FREE, if you have any CBR file this is what you need!
CBR file extension is not really a file extension its a regular rar file but changed to cbr to imply its contents are images, moreover those images are part of a comic book for CDisplay
Its a compressed set of .JPEG, .PNG, or static .GIF images. Pages are automatically ordered and can be presented one or two at a time by CDisplay.