To pet the kitten, just rub the screen evenly while keeping your finger pressed to the glass. Pet slowly, and you build up love slowly. Pet quickly and your cat's happiness goes up fast. Happiness constantly drops and is only boosted by petting, so keep at it!

To tell how happy your cat is, use the Heart Meter. The if only the first three hearts are showing, that means your cat is calm, and should purr softly. The next four hearts are the sweet spot, where the kitty will purr and vibrate loudly but evenly. The final three hearts mean your cat is riled up by all the petting and really excited, so its purring and vibrating, while enthusiastic, is irregular and less soothing. Of course, your pet's mood varies a bit more than these three choices, but this is a good way to think of it.

For more detail about the purring itself, you can go to the iPhone's settings and turn on the Purrdometer. Both Purr Length and Longest Purr values are available for display on screen while petting.

Clicking the paw icon in the corner will flip iPurr over, so you can choose a new cat from the eight cute fuzzballs available, turn the heart meter on or off, toggle purr vibration, and even pick your own image to pet! To pick a new image, just hit the green kitty-head button with a question mark, and choose a picture from your photo library. iPurr will automatically save it for you so you can pet it the next time, too... use a picture of your favorite cat, your best friend, or anything you like!

That's it! Stop reading and start petting!