Tags — each book shows a tag for every person whose list it's on. Click any tag on a row to add or remove that book from that person's list — handy for crossovers. Use the List filter above to show just one person's books.
Status — click Downloaded once you've got the book (green edge), or Unable if it couldn't be found (red edge). The button will say "Tap again •••" for a couple seconds — tap it once more to actually make the change, so a stray tap can't flip a book's status. Setting one clears the other. Filter by status the same way.
Sorting — switch between Title (one alphabetical list) and Author (grouped under an author heading).
Adding one book — click + Add Book, enter a title (author optional), tap whoever's list it belongs to, then Add Book.
Adding many at once — click Bulk Add, then paste or type one book per line. Add the author after a comma if you have it, e.g. Beartown, Fredrik Backman — the author is optional, just the title also works. Tap whoever's list this batch is for (applies to every line), then Add All.
Removing a book — the × at the right of a row.
Data — everything here reads and writes the Google Sheet directly, so it's the same list no matter which device or family member opens this page.