Just when you thought iPhone app developers had seized every thinkable opportunity out there, along comes this one: Now, you can potty-train your kid using a free mobile app from Kimberly-Clark. The maker of Huggies diapers and Pull-Ups training pants is introducing a new app, iGo Potty, this week that does just well, exactly that. It encourages both parents and kids alike to participate in the potty-training process (and hopefully make it fun along the way) with interactive features like customizable potty reminders, prizes and games and even special calls from "Patty the Potty." (Yes, the toilet is calling. Make sure you get your toddler to answer it.) What's more, upon successful completion of this important life stage, the app lets out a stream of graduation-themed music, as well as (virtual) balloons and streamers. There's even a diploma you can print out and hang on the fridge. Mobile marketing agency Joule created the app. We can't wait to try it ourselves. Does it work on a dog?