Sell something for me on phones (E Marketing)

I need some help with getting 500 downloads and reviews of an android application on Android devices the target time is 30 days. this amount $30 is for 500 downloads and reviews atleast but if such marketing person give me atleast 30 active users for this product from any country, he'll be paid 20% of the all earnings. earning details will be shared with selected Freelancer only, so, he'll know every statistics of it. looking forward to get a better person.