Amplenote - Write it down. Get it done.

https://www.amplenote.com/

Take your best ideas from hunch to launch with Amplenote
Shape thoughts into actions
- Stop losing work in the shuffle between apps.
- Amplenote offers four modes that bring your best ideas to life.
The best note-taking app for to-do lists
- Don't take our word for it, listen to what the experts and real-world users are saying