Thanks for reaching out about that, @aunpric!
I’d like to quote a comment one of our developers left in this interesting article about the Progressive Web Apps, which I believe thoroughly replies to your question:
We are gradually introducing PWA features to Jetpack as they are ready, and according to which give the greatest user benefit.
In Jetpack 5.6 we introduced the “manifest” feature of Progressive Web Apps, which can be enabled (currently) via the modules page at yoursite.com/wp-admin/admin.php?page=jetpack_modules
We have also introduced additional performance features that came out of our PWA work, such as Lazy Images (which can also be enabled via the jetpack_modules page).
So far all these features have been made available for free. We don’t have anything to announce in terms of paid plan features just yet.
We are excited to announce support for more PWA features in 2018!
Hope that helps! Let me know if there’s anything else we can do to help.