Good luck with your book! You can set your book completion percentage here:

Author > Books > [Book Title] > Book Web Page ? Book Status

The percentage you set will be displayed under your book's cover image on its Leanpub web page.

It's also a good idea to mention that the book is in-progress in the About the Book section, with some information about your intended publication schedule; this gives potential readers confidence that you'll finish.

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