New marketing site discovered - is it real and safe to use?

I am looking for effective and safe, for developer’s money and developer’s apps, app promotional sites and recently found this one.

I did a little Google research and found almost nothing about somebody experience with the site and the service they provide.
I am looking for a paid promotion of Android apps that really works.
The same time it is important to me to be sure they use legal methods and do not involve risk to the apps, to be suspended from Google Play.
The service they provide is very attractive, it is not cheap, but unique in whole Internet.
The fact that nobody mentioned it before is suspicious for me.

Please, everybody,
reply with information that can help.

Best regards,

It looks quite cheap for what they promise actually. And their site is badly designed.

I agree about “cheap”, for example for iOS apps exists site that request thousands $ for same service, but 600$ is also serious expances when you do not sure about the results.
Also, I found that the site exists for 6 months only. Poorly designed - yes, there is a reason - only two people own it, not a big company.

My advice: Stay away from that service.

First of all: Top 20 for what and where?

Secondly, and most important: If the same site claims that one of the owners is able to create apps himself, he should be making his own apps and becoming rich positioning them by his own means right?