A free program for Android, by Blitz Mobile Studio.

Idle Zoo 3D is the best city zoo simulator for Android. You can now become the real zoo manager in this exciting animal simulator. This game has everything you need to build your very own zoo. From the exotic animals you will be able to get the most interesting animal species in the entire world. To make sure your zoo is up and running, you will have to take care of all the needs of the animals. The most important thing is to make sure they are all satisfied. To do this, you will have to make sure they have food, water, and a place to live. 

The best thing about this game is that it is a real simulator. The animals will behave differently depending on the conditions in which they are placed. For example, if they are in a cage, they will behave differently than if they are in a place. The same goes for the behavior of the people in the zoo. You can interact with them, and they will react differently to your actions.