As a kid I always remember my mother having one of these which had a color-coded calendar and an address book. (This of course was years before any smart phone let alone cell phone was available.)
If you want to talk about an organized person then you should meet my mother. Our chores were listed out and rotated each week as was listed on the family calendar. Each of us kids was designated a specific color. The large calendar on the refrigerator had to be filled out and highlighted with your designated color each week so that schedules could be accommodated for events and noted the level of chores we were responsible for that week. If chores were not done properly you knew who was in trouble. The regiment must have made life a lot easier for a single-mother raising three girls and her organization rubbed off onto each of us.
I do use my phone calendar, but it does not have the visual appeal that works best for my organization style. I like to see all events for the week and month at one time and have different colors for different genres. My phone makes the color coding a little cumbersome and the view settings are limited. In the weekly view you can only see a few hours for each day rather than the entires days schedule of events. Also, I am a list maker and note taker and would like to have one place for all of these tasks. I carry around a moleskin notebook for my notes, thoughts, ideas, and lists. Why note just carry a day planner instead?
While I am in the process of honing what works best for me, I found inspiration from this video below and I hope it inspires you as well.