It's much easier than the first one (Jiggle & Bounce), and it actually works on a variety of breasts, unlike the second one (Jiggle & Grow beta). This script can do what my jiggle and bounce script did for the most part, so I will be taking those pages down for now, but the files will be archived.
Download link on Google Drive.
It's only one file this time and goes in your After Effects Script folder. (Program Files/Adobe/After Effects/Support Files/Scripts). There is a brief quick start guide over on the Jiggle and Grow Page. The short video below is me running through the process of using the script and then playing with it.
Please give it a try if you get time! I worked really hard to make it easier than the last one and came up with a really odd way to get it to work, I'm kinda proud of it. The script file is the source code, so feel free to open it in your favorite text editor and look through it.
The script is free, but you know, maybe a shoutout wouldn't hurt the first couple times you make something with it.
(Thanks Litch @ begrove! And congrats on the new house!)
I do have plans to upgrade this script (in particular adding the ability to handle two breasts in one mask for clothed breasts), so if you have a feature or something you want to see if I can build, please let me know on the Jiggle and Grow Page and I'll comment whether it can be done.