Subway Idle is a free mobile game developed by App Swim LLC under the Games category. It is an idle metro simulator that challenges players to build and maintain a subway map for a growing city. The game features multiple cities to progress through and tons of upgrades to advance your network.

In Subway Idle, you start by connecting stations between other stations and getting your trains running. As new stations open, you earn more money and upgrade your metro even further. The game allows you to decide where to use your limited cash flow and keep your city moving.

One of the best things about Subway Idle is that you can earn while you're offline. This means you can advance your metro even when you're not playing the game. With its simple and easy-to-use interface, Subway Idle is perfect for metro enthusiasts who want to experience the thrill of building and maintaining their subway network.