In each OpenERP module, there is a mandatory "__openerp__.py" file, also known as the manifset file, and in this file there is a section named "application" when stated to "True" makes this module appears in the "app" list.

following is an example of an __openerp__.py file :

 # -*- coding: utf-8 -*-

 {'name': 'The module name',

'version': '1.0.0',

'category': 'Category of the Module',

'depends': ['List of modules on which this module depends beside base',

          ],
 'author': 'The Authorf',

'license': 'AGPL-3',

'description': """
 The module description (text)
""",

 'data': [],

'installable': True,

'application': False,

}