Google Play Niches

Hello every one i have a question Im having lately problem on finding the best niches on google play so I searched on some tools to help me on finding it and i found apphorns my question if any one used it before or still using it do you recommand me to buy a subscription month on it or it's just a wast of money.

Sounds too good to be true, if you have a tool like this, you will sell it for $47/month or you will use for your own and make a lot of money without share your secret tool?