As I upgraded my site (Googility.com) I took some time to modernize the django-stw template tag and support API changes for the latest Django and Python versions.
I also tested the package when deployed using HTTP and HTTPS.
Here are the changes (from the CHANGELOG.txt):
1.0.1 Use https for all requests to shrinktheweb.com - Stops browser warnings when used on https websites while not interferring with sites running on http. 1.0.0 Updates for Django 1.9/1.10 and Python 2.7/3.5 - Old versions of Django/Python are no longer supported. - Removed ``shrinkthewebimage`` template tag since there is no longer an API distinction between free and Pro accounts.
The latest package is available on PyPi:
pip install django-stw