Author Terry Pratchett has a fervent fanbase thanks to his Discworld books. Soon there’ll be an Ankh-Morpock Map app for that on iPad.

A firm release data hasn’t been announced, but a teaser website has launched, complete with a video welcome message from Pratchett telling fans to keep the news “under your hat”.

Random House subsidiary Transworld Publishers will be the publisher, working with developer Agant. Fans are being encouraged to sign up with their names and email addresses to hear about the app’s release and get previews of its content.

Pratchett has sold more than 70m books in his career as a writer, so it’s safe to predict the release of Discworld: The Ankh-Morpork Map For iPad will be a big event.

Here’s Pratchett’s video: