For students writing books, CoverJig can be used to create a book cover for their work. The site works without signing in, although if you want to save progress, you’ll need to create an account. To export your picture for free, you’ll screenshot the book cover.
There are tons of tools to use on your book cover. The number of fonts are limited, but the filter tools work on text along with pictures. This gives you a ton of options to create some great looking book covers.