More quoting myself:

With other cruise lines, ones even within the Carnival Corporation family, offering mobile apps specifically for iOS and Android devices, it may at first seem peculiar that the Princess equivalent is not a native app, but Craddock explains, “I think one of the big differentiators for us, in thinking about that mobile experience, was that we really wanted to provide this foundation for the guest experience first and then look at the platform as something we then can use to expand how we do our offerings onboard.” That means it is also accessible from traditional internet cafe terminals, laptops and tablets and can be inexpensively updated more frequently.