Are there any good captchas specifically designed for mobile apps?

Question

Is there anything that is less intimidating than recaptcha for mobile apps? My app is built with JQuery Mobile and most likely will never be available on the desktop. I am hoping there is a more visual captcha that would not require typing. So far most visual captchas I have found seem too large for a mobile app. I am mainly looking for something that is visual and small enough to fit within the average mobile screen. Any suggestions would be appreciated, I would even be willing to build something from scratch if someone has a good idea.

Answer 1

I don't know if you are using HTML5 or not, but there is a pretty cool captcha that I've used called MotionCAPTCHA. What it does is it presents a shape and the user traces the shape with their finger on their mobile device. Its pretty cool. I've used it with Android and it works pretty well. It requires jQuery and HTML5.