As a single-page app, we use `window.history.pushState` to push new pages onto the history stack. When a user leaves the Marketplace (to play a game he just installed, for example) the Marketplace is no longer in focus and usually because of memory limitations on the Firefox OS devices, the Marketplace's background process gets killed. When the user relaunches the Marketplace, his history is gone, and he has to find the last page he was on. Let's persist the history stack (for a reasonable amount of time - say, an hour) in localStorage/IndexedDB, so that when a user relaunches the Marketplace (*as an app*) we remember the last page the user was viewing (and all the previous pages they were viewing). The history stack is small, and this is pretty trivial.