Add messenger to Django web app

We are currently working on a Django web app that is based on this one here ([login to view URL]). In this app each user has a contacts list of other users. We intend to have a messenger such that users can communicate directly on our Django web app and this messenger should be available on each page, though with the possibility to minimize it, such that it does not dominate each page. These here ([login to view URL]) might serve as an inpiration, but of course one might choose another one. Hence, the task is to embed a messenger in our web app in a branch of our GitHub code, that works with all the contacts a user does have and that comforts our web design.