simple time vibrator

I'm looking for help to design a simple time activated cell vibrating motor. I want to make it as small as possible and can be powered by a button cell power source. I need it to be as compact as possible without sacrificing function. I've done a lot of research but what I'm coming up with is either to simple or too complex for my understanding. What I'm after is not them to build this device. Only to give me a list of parts that would work together for this purpose, and how to assemble them to accomplish said function.