Just going to give you guys an update on the "Sizebox" topic:
I downloaded Sizebox and it was the most engaging GTS themed game I would ever play. Not only can you scale the giantess model's sizes to your liking, but you can make them slowly grow larger (even in spurts!)
You can go here to download it free:
https://www.patreon.com/Aiiko
And here is where you can find a lot of free models:
http://macrochan.us/v/res/357.html
And to prove how much I enjoyed this game, some screenshots. Enjoy!