XnRetro is an image editor for Mac users who wish to give their photos a vintage feel. This program offers simple to configure output options, provides you with quality results, and lets you share the processed photos with friends on Facebook, Flickr, and other social networking websites.
Besides supporting common image formats, such as JPEG, GIF, PNG, and TIFF, this app also works with CIN, DCX, DDS, IFF, and many other photo files. After you select an input image, you can choose from a wide range of vintage visual effects, adjust color balance levels (brightness, exposure, etc.), and export the resulted photo.
A good thing is that the app lets you preview the image as you configure its output settings. This way, you can know for sure if the outcome matches your needs or not.
An aspect I don't like about XnRetro is the fact that it doesn't offer support for batch processing. As a consequence, you can't modify the appearance of a large amount of photos at the same time. What's more, the application lets you export the result to only two output formats: JPG and PNG.
If you ask me, this program is worth a shot. The app is very simple to use, supports various input formats, and offers a wide variety of vintage effects and output configurations. Furthermore, the program is free of charge. So, I can't find any reason why you shouldn't try this image tool.