Book Creator for iPad
Book Creator for iPad has been around since 2011. It is a downloadable app that is installed onto your iPad and can be accessed completely offline (with some online features). Students do not sign into Book Creator for iPad, and they cannot access the teacher libraries created with the online app. Book Creator for iPad does not have libraries in the same way the online app does.
Book Creator for iPad costs $2.99. This is a one-off cost per device, which you pay once and can then make unlimited books.
If you want to use Book Creator for your own personal use at home, you must use the iPad app, not Book Creator online.
Book Creator online
Book Creator online launched in 2017. Originally available only on the Chrome browser, it now works in Apple's Safari browser and Microsoft Edge too. To use Book Creator online, teachers need to create an account, and invite students to join their library to create books. With a free account teachers get 1 library with the capacity for storing 40 books.
What's the difference?
The main difference is that students don't need to sign into Book Creator for iPad. This means they create books which are stored locally on that iPad, and won't be available on other devices unless you manually send these books.
Books made in Book Creator online are accessible on any device that you sign into. But note, you cannot see them in the Book Creator for iPad app (as you don't need to sign in).
So, if you need to transfer books between the online and offline apps, here's how you do that.
The only other thing to consider here is that Book Creator online is available on iPads in the Safari browser, so if you want to use that instead of the downloadable app, you can.
The pricing for the two apps is completely separate. Purchasing Book Creator for iPad does not give you access to a paid subscription for Book Creator online, and likewise if you pay for a subscription to Book Creator online this does not include the iPad app.
Most of the creativity features are exactly the same across both versions, but there are some features that only work in the online app - for example the built-in Google image search (which requires you to be online), and the fill tool for drawing.
When it comes to sharing, you can publish whole libraries online, but in the iPad app you can only publish single books (up to 10 maximum). However, you can export your book as a video with the iPad app, which you can't do with the online app.
See a full list of feature differences between the online and iPad apps.