I stay as organized as I can.
I'm on android, if you are too, check out these apps:
https://www.any.do/to-do-list-app-for-android/
Anydo has a little widget on my homescreen, one tap and I can voice-dictate a task if I'm pressed for time, or type it out with further details.
Syncs with Google Calender but has a nicer interface.
Every single event or appointment has multiple alerts.
And Trello for larger tasks, projects, milestones for tracking my projects.
And Obsidian for taking notes (not on Android through, but on my laptop).
I have a Pixel, so not sure if this is available on other devices, but I frequently just speak to my phone and this launches Google Assistant.
I can be driving, or watching a movie, or cooking and I want to add a task or a quick reminder. This literally takes me just 5 seconds ...
"hey google, set a reminder to pick up milk from walmart at 5pm", or
"hey google set a timer for 90 minutes", or
"hey google send a text message to james thomas, hey whats up?"
I like any.do as my short term todo list.
When I end up pressing "remind me tomorrow" on 10 items each morning, I tend to feel like it's time to work them down, and live my life less procrastinatingly.
Reminders are set to 7:20 which for me is when I arrive at work, wait for the coffe machine, and am first able to actually process what I'm clicking "remind me tomorrow" on.
Ok here's a actually good one that fits all ur requirements (there is a premium subscription but the things it adds are things that are less useful/useless) https://www.any.do/reminders-app-for-mac/
I personally recommend any.do. Even though it is primarily a to do app, it has really good calendar features and is able to sync your tasks accross many different devices. It has a premium version but its free version is pretty complete already.
I like the idea. There is a similar app called anydo https://www.any.do/ that gives you positive reinforcement when you're plowing through tasks although I don't think it's really branded toward self improvement specifically.