The phrase usually refers to finding ways to progress faster without spending real money. While third-party "cheat engines" or "unlimited diamond generators" are typically scams that can compromise your account, there are several legitimate, developer-approved ways to get free rewards and optimize your gameplay.
Leave your game open overnight. Seriously. The "Offline Gathering" mechanic is terrible. But online gathering gives you 300% more resources. Use an auto-clicker (allowed in some versions) to keep your character gathering stone in a level 6 node while you sleep. Wake up to free resources equal to a $20 purchase. game of thrones winter is coming cheats free