Since opencart 2.0.1 each time you create a module instance fom the main module , this gets added to the modules list. If you create a lot of modules you will have a very long modules list and will be pretty difficult to find a module in the big list.
I made a small ocmod that will group created modules with the main module in the list and you will have a +/- button to expand or hide those modules.
If you like this ideea you can go ahead and download the ocmod for free here: http://www.opencart.com/index.php?route=extension/extension/info&extension_id=20053