In some cases, you may need to manually add your software to Lightroom. To do so, please follow these instructions. Mac and Windows instructions are provided. Blow Up 3 is used as a reference, but the same can be done with Exposure, and Snap Art.
I will use Blow Up 3 as my example, but other products can be done in the same way.
Open Lightroom and then open your preferences.
Mac - Lightroom > Preferences
PC - Edit > Preferences
Select the External Editing tab.
Then click Choose, and browse to the Blow Up 3 application file.
Mac programs can be found in one of two places
Macintosh HD > Library > Application Support > Alien Skin. In this folder, just choose the folder for your plug-in and then select the application file in that folder.
Macintosh HD > Applications. Then locate the plug-in you wish to add to Lightroom as an external editor.
Windows programs are all located in the same place.
PC - C:\Program Files\Alien Skin\Blow Up 3\Alien Skin Blow 3 x64.exe
Then click Save Current Setting as New Preset from the Preset drop down box.
It will then allow you to name this new preset.