Should I open the iOS web application before the application is cached (cache manifest)?

I need clarification.

My webapp is cached in safari. When the flight mode (wifi off) is on, everything works fine.

When I say "add to desktop", the application only works when I open it using wifi. After that, the application works great offline.

Is this the expected behavior?

So far, I realized that cached data (including localStorage stuff) is being transferred from safari to webapp.