Need Simple List App with Copy/Paste or Import

[mel2000]

I'd like recommendations for a simple list app that allows me to import or copy/paste a text file list from scratch. Must assign a separate checkbox to each imported list entry. Would like a simple checkbox on/off toggle to denote which list items are done. Must sort alphabetically. Google Tasks, Google Keep, Chore Checklist and Listy do NOT do what I want. Thanks.