This is the app called Franco Kernel Manager, one of the best kernel managers that are out there... Even when it was outdated (which I think that's the cause it got booted from the PlayStore?).
I used it to check the process of my phone and monitor the active and idle drain mostly, I paid for it a long time ago, but now it just fails to check the licence and it doesn't let me use it fully... I think there must be a cracked APK over there...
EDIT:
Fortunately the app is back in the store and hopefully that update version comes soon enough!
I think if more people took that path, pirate only when you actually have a problem, much less content would be cracked and piratable.
Imagine OP and someone who is capable of cracking a software both bought and used this app, then 3 years later the app stops working. OP goes to look for a crack, but one doesn’t exist because the person who would have made it happened to stop using it before they had a need to crack it. So now OP is just boned.
So I say, always pirate everything and do so asap. And then obviously, if you want things to keep being produced, you should probably support the creators.