Best word of the day app(plication)?

Heya,

So I'm looking for a good app that can help me learn the top most frequently used German words. I have a few vocab lists, but I don't exactly want to be memorizing them from top to bottom - rather they're better for checking to make sure I know the words.

Anyways, what do you guys recommend for a "Word of the Day" application - just something that pulls a random word from the most common/used German words. I don't want random or obscure words, I'm looking to expand my vocabulary for every day German.