A well-designed web app will have a version number embedded in the filename(s) of the large file(s), (like the filename of a minified JavaScript file containing

A well-designed web app will have a version number embedded in the filename(s) of the large file(s), (like the filename of a minified JavaScript file containing the entire app) so that upon first visit to the page the app is downloaded and "installed" (cached), but on subsequent visits your browser grabs the file from its local cache. This is really a seamless and excellent form of deployment, and when done correctly the browser only waits for new downloads when a new "version" of the app has been deployed to the server. So well written SPAs like meta64 do have the "install this app once, and run many times" behavior.