The November 2015 ArcGIS.com update has a new feature listed for Web AppBuilder where the app automatically saves your last location and layer visibility for the next time you open the app. HOW DO I TURN THIS OFF? This seems to be causing issues with map layers not loading that are coming from our internal server. Plus, I want all the layers to go back to the map default each time on map open.
I don't see an configuration for this new feature. So you can not turn it off currently. I would call esri tech support immediately and get this logged as an enhancement request.
Further testing, the issue we have relates to grouped layers in the table of contents of the Web App. Previously we had for example, several districts that were all checked on, contained in a group layer that was checked off by default. So if a user wants to see all the districts, they just had to check on the group. After the November update, when the app "auto-saves" on close, the next time you open the app, the grouped layer and all its subordinates are all un-checked. So the user who was used to just checking on the group layer, now does so and nothing happens. They have to expand the group and check all the layers on one by one.
I checked the ArcGIS.com map that controls the Web App, and group layer is un-checked and the subordinates are still all checked as they should be, and as by design before the November update.
Sometimes all you need to do is read the help menu. ESRI clearly states that if you use several of their new URL parameters, it will not save app state on close. So I simply added "&level=16" to the end of my app shortcut url (my map started at zoom level 16 before), it starts out at the default map extent like it used to, and the issue with grouped layer subordinates being un-checked also goes away.
I guess I would prefer an option in the web app builder configuration page about saving app state, but for now, this workaround will do.
Based on that documentation you linked, clearing the cache will clear the app state info. So, would this indicate the app is using HTML5 local storage for any user accessing the apps?
As the Developer version is not out yet (for v1.3) I have not looked under the hood of this new feature to see exactly which mechanism they are using but local storage with a fall back of cookies would be my guess.
Sure they are using a new class called the AppStateManager and this class uses the libs/storejs/storage and libs/md5/md5 to store the data in local storage of browser after it has been hashed using md5.