You can download and use the MultiFill and Flatten plug-ins for free. Flatten Pro is not free. You need to purchase a serial-number before you can use it.
There is no installer, just put the plug-ins anywhere in your Photoshop plug-ins folder after extracting them from their archives.
Extract the plug-ins from their archives, or open the diskimage. Find your Photoshop folder in the Applications folder on your computer. It is called something like "Adobe Photoshop CS4". Inside the Photoshop folder find the "Plug-ins" folder. Copy your plug-ins there. Restart Photoshop and you should see a BPelt sub-menu in the Filter menu.
Extract the plug-ins from their archives. Then find your Photoshop on your computer. It is normally in a directory like Program Files\Adobe\Photoshop.
Note that on 64-bit Windows, there is a 32-bit Photoshop folder and a 64-bit Photoshop folder, both with their own
Another option is to tell Photoshop to look for plug-ins in a specific folder. Make a folder somewhere convenient for you. And put all your extra plug-ins in there. Then in Photoshop open the plug-ins preferences and choose an additional plug-ins folder. Restart Photoshop.
Photoshop 6 - Photoshop CS2The Mac plug-ins contain Mac OS X and Mac OS 9 versions. Use Stuffit Expander to extract the .sit archives.
MultiFill Macintosh (Free)
Flatten Macintosh (Free)
Photoshop CS3Universal binary plug-ins for Photoshop CS3 and newer.
MultiFill Macintosh CS3 (Free)
Flatten Macintosh CS3 (Free)
Photoshop CS5 64-bit
64-bit Intel plug-ins for Photoshop CS5 and newer. These plug-ins only work with CS5 or newer in 64-bit mode. There is no free 64-bit Flatten.
The plug-ins are in .zip archives, please extract them before use. Search with google for extracting zip.
Photoshop 6 and newer
These plug-ins work with Photoshop 6 and newer. Note that these work only with CS4 and newer in 32-bit mode. For 64-bit CS4 and newer see below.
MultiFill 1.5 Windows (Free)
Flatten Windows (Free)
Photoshop CS4 and newer 64-bit64-bit plug-ins for Photoshop CS4 and newer. These plug-ins only work with CS4 or newer in 64-bit mode. There is no free 64-bit Flatten.
MultiFill 1.5 Windows 64-bit (Free)