Missing Android Tablet Apps?

Okay guys, so I'm really curious, which applications (from other platforms or not) do you think are missing on Android Tablets? Is there some sort of App you wish existed? I don't necessarily mean specific things like Facebook, but I'm looking more into the type of app. Help me out here.

I am curious, not just because this is one of the huge gripes with the Android ecosystem, but because I'm considering some development and want to make something people would actually use.

Thanks for your time. :)