How do I do that in ios skritter?

by a series of single taps?

Tap once to show stroke by stroke, tap and hold to show the whole character.

tap and hold isn't working for me

tap once to show stroke by stroke isn't working either

I don't think there is any "animation" available the way the web version does when you hold down the "?" button. But for me at least on the iPhone if I tap once it shows me the first stroke. I can then draw the stroke, tap again in the drawing field, and see the second stroke. I'm not sure if you can draw the whole character this way or if it will give up and mark you wrong. A short cut is to double tap to reveal the whole character (same as clicking once on "?" on the web site, but this does not help with stroke order.

It does mark you wrong if you do that for the whole character but it let's you do the whole thing.

Also, sorry, tap and hold was wrong, it's double tap as podster says.

Stroke order is pretty obvious for most characters. I suppose a stroke order diagram could be considered "nice to have" for some, but it is probably unnecessary for most people, as Skritter alerts you on the odd occasions you get the order wrong.

With a few extra taps (quite a few) you could view the stroke order in Pleco...

》 I'm not sure if you can draw the whole character this way or if it will give up and mark you wrong.

It will mark you wrong, but you can keep tapping and tracing stroke by stroke all the way to the end of the character.