I use this app on a daily basis. But damn, why can't they add a couple of single color backgrounds to choose from? Just add a white BG and I'll be happy.
I know. That's really annoying. I ended up just replacing one of the defaults in Applications/Wunderlist/Contents/Resources with a custom one. Although, you'll have to redo it every update.
I think with the addition of folders, Wunderlist is bar-none the best to-do app on the market. I love using it. It doesn't make it any easier to actually get things done, but it does make it fun to capture those things.