Which tool should I use?

Pick by what you're trying to produce:

• A print cover (the full wrap — front, spine, back, barcode) → Cover Maker. You bring one front-cover image; it builds the rest for KDP, IngramSpark, Lulu, or B&N Press.
• The inside of the book (a print-ready PDF and an EPUB ebook from your manuscript) → Interior Formatter.
• The copyright page and front matter (title page, copyright, dedication, and the back-of-book pages) → Front Matter generator. Free.
• Marketing images of your book (realistic 3D shots) → Book Mockups.
• A video or social-sized stills (a cover reveal, a book opening to a real page) → Social Pack. Covered by the same unlock as Mockups — see Can I make a video of my book?
• Amazon "From the Publisher" images → A+ Creative.
• Advance copies for reviewers (watermarked, or emailed with tracking) → ARC.

You can use one tool, several, or all — they share the same book, so nothing has to be re-entered. And there is nothing to decide about which of them to pay for: one price covers every tool for that book, whether you use one or all of them.