@Olo it is very cool! And mostly free (some purchases if you want extra assets).
Another advantage for me is it lets me easily visualise the scale of the subjects at different levels or against different parts of the body. For example, a tiny might not seem so tiny when in the hand, but it’s different if they’re on the ground next to a foot. Or even if placed on the shoulder. Thanks to that, I’ve been able to settle on a single preferred ratio for my fantasies, rather than keep questioning whether someone is too big or too small.
And on the topic of being swallowed whole, the app’s also helped in realising whether the tiny is too big (or the giant too small, whichever way it may be).
Otherwise, I’d been relying on articulated artist’s models for a long time - more recently, I found a 4" one that’s been amaaaazing and I love her.