I don't, but good on Apple for exposing that functionality. My understanding last time I looked was that in Android it's not even exposed to developers (though I didn't look too deeply into it - there may just be no native API functions for manual focus).

As far as I know, if you're in the stock camera app, you can tap a portion of the screen for the camera to focus on that area. My girlfriend has an Android phone and can do the same.

tap is to autofocus. So if the autofocus is wrong, enjoy your frustration, miss your picture, or enjoy your blurry picture.

Tap and hold in iPhone camera app locks the focus, you can then move the phone to manually focus.