'List apps.
If ctr (subcategory ID) is None, returns a list of valid subcategories.
If ctr is provided, list apps within this subcategory.'

def list(self, cat, ctr=None, nb_results=None, offset=None):

    path = ('list?c=3&cat=%s' % requests.utils.quote(cat))
    if (ctr != None):
        path += ('&ctr=%s' % requests.utils.quote(ctr))
    if (nb_results != None):
        path += ('&n=%s' % requests.utils.quote(nb_results))
    if (offset != None):
        path += ('&o=%s' % requests.utils.quote(offset))
    message = self.executeRequestApi2(path)
    return message.payload.listResponse
