I’ve been playing Paragon Pioneers for Android and it is rapidly becoming one of my favorite idlers ever, maybe one of my favorite mobile games ever.
It’s a city building/production game where you have to conquer and colonize new islands in order to produce products that make your villagers happy. The game is very attractive, the interface is slick, and the pace is the perfect mix of idle and active for me. It costs $4 upfront but with no ads or IAPs and you can play completely offline. Well worth the cost IMO. There’s a demo you can check out for free.