How safe is this?

Hi there!
So I have just come across this app, can someone explain to me how it exactly works? Is it an injector?
Im interested on purchasing a week subscription to try it out.
However, how high is the ban rate? Will it be okay if I use this once every few games? So its not constant in every match?

Thanks.

So far. there is no ban wave. I can say 90% safe.