I'm feeling absolutely with you! I love to keep things simple and using the GTD approach. This works quiet well using the Apple Reminders stock app. However, one thing I felt was always missing, is a visual report to keep me accountable and on track. That said, I've built Progress for Apple Reminders, a way to set goals on Reminders and to visualize how your doing using a simple progress bar: https://progress.rocks/blog/vision/the-story-behind-progress-for-apple-reminders/ If you're relying on Apple Reminders in your productivity system, give it a try!