Stop reloading of web app launched from iPhone Home Screen

I just found this related question on SO: Stop native web app from reloading itself upon opening on iOS

As it seems it's a limitation of Safari, a proposed solution is to persist your web apps state using Javascript and HTML5 localStorage. When your web app is launched, check for the persisted state and load it if available.

You can read about using localStorage in Safari here: http://developer.apple.com/library/safari/#documentation/iPhone/Conceptual/SafariJSDatabaseGuide/Introduction/Introduction.html#//apple_ref/doc/uid/TP40007256-CH1-SW1

Hope that helps you. At least it did for me, as I had the same problem as you. :-)

I found a hack, tested on iOS 11.4.1/12.0
Open file uploading window and then switch back to the home screen.
The app still continues to work, in my case audio is playing and localStorage is updating

Proofs:https://youtu.be/heehLUhGKYY

PS. note how song progress changes when we seek, it proves that app works in the background

The short answer is that you can't control this. Sometimes iOS will keep a web app active in the background, at other times it will kill it. It's entirely related to how much memory is available on the device.

So, your best approach is to minimise the problems presented by this reload. Make sure your webapp updates the URL when you move from view to view, either by changing location.hash or using history.pushState(). This will allow you to reload whatever view the user was on before they switched apps. There are pagehide and pageshow events that allow you to execute code when the user moves away from your app - take that opportunity to store local state in localStorage and/or IndexedDB, then fetch that data again when the webapp is reopened.