I made a thing: The Season Journey Tracker!
http://d3resource.com/journey/
Here's what it looks like in action:
Super simple concept - just as you doing the Season Journey click on a task to keep an overview of what you have done and what still needs to be done. The status is saved in a cookie. Pay attention to the in-game popups because you can complete many season journey objectives that aren't even visible yet, so this website might help you to keep an overview.
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