Pacman

Pacman is a lightweight and easy to use Parallel API Calls Manager.

You might need to execute multiple API calls at once to speed up loading of your app and proceed only when you have the data from all the required API calls. Managing this using normal boolean flags or such methods can be a pain and can result to incorrect data or behaviour.

That is where Pacman comes to play, as you just set it up with some CallGroup, make the API calls and then update Pacman as and when you get a response from the call.

After all the calls are done processing, Pacman will fire a callback to an attached listener ( which you have set up ) and then you have do whatever processing you needed to do after the calls were done.

from The Android Arsenal