WallGen 1.2 for Mac was available to download from the developer's website when we last checked. We cannot confirm if there is a free download of this app available. The software lies within Theming Tools, more precisely Wallpapers. This free Mac application is a product of Sergey Nes. Please check the Mac app with an antivirus before launch as it is downloaded from the developer's website, and we cannot ensure that it is safe.
From the developer:
WallGen is a simple application that offers an easy way to place your family photos on the desktop. All you need to do is drag and drop the photos into the program, place the pictures in the desired spot, add a frame if wanted, and resize the photo to custom sizes.
You may want to check out more software for Mac, such as App for the milk, Desktop Saver or FreeRangeJack, which might be similar to WallGen.