Threes!
Pros: Easy to learn, seems simple but requires thinking, addictive, great in short bursts, very clean UI and design, premium game, playable with one hand.
Cons: Gets repetitive, RNG can screw you at times.
The first number merge game still holds up. It’s fun and the design is timeless. No ads, no weird currencies, just pay a small fee once and play. Recommended.