Save your own words
Add words and translations that matter to you, edit them when your understanding changes, and keep a personal list you can return to.
Why it exists
The best vocabulary is not a generic deck. It is the words you chose because they appeared in a book, a conversation, a song, work, travel, or one of those tiny moments where a phrase suddenly becomes yours.
This idea has been tested the old-fashioned way: my wife has used this approach for about ten years. Keeping words in front of her made review feel natural instead of like a chore. The Android widget continues that habit by placing a small card where she already looks during the day.