What's a good iOS app to mock up some tattoo designs before I actually get inked? Don't want no regrets later.

Alright, so I needed to figure out if that barbed wire thing I was thinkin' about was actually gonna look as badass as I thought. Found this app, AI Tattoo Generator: Tattooist. No BS, it lets you play around with different designs and see how they look on a picture of your own damn arm. The tutorial is useless, like trying to read blueprints in a hurricane, but once you figure it out, it's solid. I wouldn't say it's built like a brick house, but it hasn't crashed on me yet, even when I'm usin' it with gloves on at the job site. Battery life seems okay, but I haven't used it for more than an hour at a time. If you're lookin' for somethin' to give you a preview before you commit to a permanent mistake, this'll do the trick.