Comic Bookie is a very basic Comic Book reader for the Mac. It currently only supports a single format: CBZ, which is basically a zipped file which usually contains PNG or JPEG images that are configured to be seen sequentially. There are other, more popular formats for comics, such as CBR and PDF, but this app doesn't accept those.
This application's main strength is its ability to open and render CBZ files quickly and smoothly. The graphical user interface is very simple, which is a plus. There aren't any special features or unnecessary buttons. In fact, the viewer only has 7 buttons that let you navigate the comic books, and a drop-down menu that you can use to choose how you want the application to adjust the size of the images. There are three options. The first one automatically fits the width of the images in a single page, the second one does the same but with height, and the third one lets you browse your comics two pages at a time.
As I noted above the format support isn't great, so i tested the app with a CBZ file that I downloaded from a website that the developer of this app recommends. You can get your files anywhere you want, though. The file was 33 megabytes in size and it loaded quite quickly. I didn't experience any slow-downs browsing pages and the text was readable and quite crisp when I maximized the window. Unfortunately, there isn't a full-screen mode.