Best lightweight note-taking app?

Looking for an app for note-taking with the following features:

• No ads ever
• No nudges to upgrade, subscribe, unlock premium features, or any bullshit like that.
• No recurring fee (ok paying up-front for the app)
• Clean, simple interface

That's it. I don't need multimedia, multi-device syncing, cloud storage. I just need a place to write down ideas and grocery lists.

Recommendations?