I dont use review sites, to me it is just a waste of money, and Google eventally finds out and bans your apps/account. I just publish extra apps and get all organic installs. You can also publish app to opera to get a little boosted start from installs from opera. Opera will make users download from play store.
It redirects user to gp store. However the stats of opera for downloads are inflated, because they count each click as download, but they dont confirm if user really downloaded it in gp.