I have two suggestions, which aren't related to each other at all, but since I've been told not to start too many threads, I'm doing a two-in-one.
The first one is about the history blurbs on the bottom of the Skritter home page. I go to read these on a regular basis and I've noticed that most of them are of the same nature: Mao ZeDong, WWII, Communist Party this and that, Chiang Kai Chek, etc. We're talking about China, here. The country that boasts 5000 plus years of civilization and one of the richest histories in the world. There's got to be tons of stuff that are far more interesting. Of course, I realize that Mao had a huge effect on China, but so did previous leaders and there's more to learn about than leadership/government anyway.
The second thing is about hiding the English when practicing tones(only). When we practice tones, the characters are shown to us and we have to enter the character's tone. I've noticed that a lot of times, I'll look at a character and then peek at the English definition, which will make me remember the Chinese translation, which will then make it easier for me to input the tone. So basically, instead of practicing being able to recognize a character and input its tone, a lot of times I just look right over to the English and see something like "difficult" and then automatically think "that's nan2 in Chinese" and then input 2nd tone. The problem is that I might have actually not been able to recognize the character 難, or mistook it for another word/character had I not been able to see what the character means in English. So I really think that being able to hide the English while practicing tones would be great.
I've tried making the page smaller/etc, but sometimes I want to be able to read the example sentences/etc, so I think that if we could choose "hide English" in the settings, that would solve this problem.