When Skritter is just drilling tones, a shadow image of the hanzi appears, I think it would be useful if the pinyin could be disabled in order to force us to remember pronounciation and tone as well.
Since some users like and other wouldnt like, perhaps a toggle in the settings would be useful.
Sorry Skritter creators, we are like children asking that and those, the good side is that we love Skritter.