While struggling to find a daily to-do planner that was simple and minimalistic, I realized I could create my own, and that's precisely what I did. So finally, I made something that I'll use every day.
TaskSpot is a free to-do planner that is simple and doesn't require a login. Start using it now by going here: https://www.taskspot.app/
If you have any feedback or feature requests, let me know.