Is there such a thing as a WIFI boosting box?

Ok so heres the thing im moving to a little island tomorrow to start new job, now the place does have wifi but it doesnt reach to the staff quarters if it does its very slow, one bar if lucky, is there such a device i can buy that will boost the wifi to where i will be staying so the signal i pick up on laptop is quciker an better, so kinda like i plug it in, it picks up the wifi, ive got better signal, is there such a device?