A free app for Android, by Idle-Games.

Idle Heroes, the new real-time strategy RPG for mobile devices, brings you a brand new world full of magic, mystery, and adventure! It is the end of the world, and the beginning of a new one. You will lead your army of heroes into the ancient ruins to battle the forces of darkness. There are a lot of heroes to choose from, and they all have different skills and abilities. Some of them are warriors, others are archers, and others are magic-wielding sorcerers.

You will have to fight the enemies in the ruins, and defeat them to move on to the next level. Every level will be more and more difficult, and the enemies will be more and more powerful.