Check out the offers you can make using this plugin

Buy 1 and get 1 free of the same product

Buy 3 and get 1 free Offer that will start at some time in future

Buy 1 and get 2 free of different product

Buy 1 and get 1 variable product free (you can change variation of the free product)

Buy 1 and get 1 with option to select the 1 free product from list of products

Category based rule

Buy product from category get product B free