Ideally one that can keep short and long term separate... and isn't "notes."
  1. Get it done app
    Suggested by @Boogie
  2. Clear
    Very aesthetically pleasing and makes a very satisfying chime noise once you've checked something off. You can change the color scheme and have a bunch of separate lists within the app.
    Suggested by @emmalou
  3. I'm a big fan of anylist bc you can make multiple lists, share between people and there's a grocery option that splits food into grocery sections.
    Suggested by @ashleyanwiler