First of all: Hi and welcome to Android Forums!
Second of all: To answer your question, those are BOOTLEG sites who are pirating the software. And Android Forums not only doesn't condone or tolerate piracy, we strongly advise against it.
When a developer works hard on an app or game, they deserve to be paid the modest fees they get: it rewards their hard work and encourages them to write more apps and games. But then some site "cracks" the app and posts it for free, and the developer is completely robbed. How would you feel if they did that to you?
Worse: many of these cracked apps & games that are "free" aren't really free. Often those who cracked the game insert spyware or malware
code into the app, meaning that you are losing your personal data to heaven-knows-who so they can do who-knows-what with it. Or they can control your phone remotely, turning it into a zombie spam device or part of a botnet. And you will likely never know.
That's why we don't tolerate discussion of it, links to it, or procedures to crack apps. I hope you understand and that answers your question
Again, it's a great forum to hang out in here, just not for the purposes you came here for