Keep an eye on official live streams and community forums. Developers regularly release active promo codes that give instant gems and gold directly to your in-game mailbox.
The APK (the app you install) is just a client—a fancy window. Your "Money" (Gold) and "Gems" (Essence Stones) are not stored on your phone. They are stored on Netmarble’s secure servers. Every time you spend a gem, the server checks: "Does this player legitimately have this currency?" solo leveling mod apk unlimited money and gems