Most mod packs for v1.2.6 bundle an ad remover. In the base game, watching ads doubles your shift payout. The mod simply injects the double reward without forcing you to watch the 30-second video.
This is the safest route. The game frequently runs "Gold Rush" weekends where coins are 50% off. Spending $4.99 legitimately gives you a booster pack that multiplies your shift income by 5x permanently. You get unlimited money without breaking the game's integrity or risking your device. bus simulator ultimate -mod unlimited money- 1.2.6.apk
If the security risks concern you, consider these legitimate ways to earn fast money in Bus Simulator Ultimate: Most mod packs for v1