Django Custom Template Tags In Google App Engine

I am trying to include the following Tag In Google App Engine Web Application:

http://www.djangosnippets.org/snippets/1357/

Is there any configuration of this file to make it work with Google App Engine?

Cause I followed the Django Template tutorials: http://docs.djangoproject.com/en/dev/howto/custom-template-tags/

and have this structure:

templatetags/
    __init__.py
    range_template.py

in the Template file, I have {%load range_template%}

But I am getting the error:

TemplateSyntaxError: 'range_template' is not a valid tag library: Could not load template library from django.templatetags.range_template, No module named range_template

The other thing that might be a problem why this ain't working is, the INSTALL_APPS settings.py file. Not sure how to configure it.

I have a settings.py file in the root of my application and included this:

INSTALLED_APPS = ('templatetags')

Any advice would be greatly appreciated.