All that info should be baked into the app.
Probably to get App Store info about it. Developer, version number, etc.
That symbol isn't only used for loading things from the internet, depending on how many apps you have it could take a little bit for it to look up all the information about each app and it has to do translations for the names of the apps from their raw names to the displayed names (such as com.google to Google Search) if you want to sort by name, it could be calculating the size of apps to show in an ordered list, it could be doing lots of things.
Apparently I don't know how to tell if users are in settings or Google Play Store, so my bad
that you need internet to see the apps though.
You can go to Settings -> Apps, and see all the installed applications. Play Store is more social kind of thing (rate, share etc) so it maybe makes a bit sense, but still could be done if devs weren't as lazy.
Never underestimate the power of untested features
It's not. App descriptions, the app name are all set up in the developer console under "store listing". You can have a different app name to what everyone sees in the Play store. Different logo, different everything.
So display what is available offline
At Least the menus work, while offline... stern look at spotify