Flask-Bibliography

This combines flask with socket.io (so there's an extra thing to learn, maybe). The author made a blog post about it that gives a little more background around it and what advantages he thinks it has over flask-sockets. He also gave a talk at PyCon Ireland 2017 that is on YouTube.

• "Flask-SocketIO Documentation." flask-socketio.readthedocs.io. N. p., 2018. Web. 13 Feb. 2018.
• "Weekend Project (Part 1): Creating A Real-Time Web-Based Application Using Flask, Vue, And…." SecDevOps. N. p., 2017. Web. 13 Feb. 2018. This is a two-part article with a fairly complex example.
• "Choose Your Own Adventure Presentations With Reveal.Js, Python And Websockets." Twilio.com. N. p., 2014. Web. 13 Feb. 2018. This example shows how to use twilio and websockets to let viewers decide what the next slide in a presentation will be.
• " Synchronize Clients Of A Flask Application With Websockets | Matthieu Amiguet ." Matthieuamiguet.ch. N. p., 2015. Web. 13 Feb. 2018. An example of how to synchronize sliders across two clients.

This is a project from Kenneth Reitz, the guy who made requests. On the one hand, it looks much simpler, on the other it doesn't look like it has as many options. Maybe a good starter that would later need to be swapped out for Socket IO if it got complex enough.

• "Kennethreitz/Flask-Sockets." GitHub. N. p., 2018. Web. 13 Feb. 2018.
• "Using Websockets On Heroku With Python | Heroku Dev Center." Devcenter.heroku.com. N. p., 2018. Web. 13 Feb. 2018. This is a more complete example of how to use flask-sockets and deploy it on Heroku.

This looks like it's halfway between flask-sockets and flask-socketIO.