Apps try to optimize user experience by maintaining the last used state when the user leaves the app and comes back to it later. This is incredibly useful when the user has to leave the app for a brief while and come back to it. Sometimes this happens when we are responding to a notification while on an app and have to then come back to it. Or when a link takes us out of the app and we get back to it. Occasionally, it is even useful when we have to leave the device and come back to it.
Some apps however take the state maintenance to an extreme. They seem to maintain it for too long, beyond the point of usefulness. Facebook is an example. Now, Pulse, Flipboard and others appear to be following suit. The problem with this is twofold. One, beyond a certain time, when I come back to an app, I want to see new content and do not even have context for where I left it the last time around. Two, when I’ve been away for long, I have sometimes passed the previous state by accessing the app on another device by then and the previous state is irrelevant to me any more. It now takes longer to back out and reset the state to a new session.
Clearly, state maintenance is not a binary all or nothing aspect. There is a period of time when the previous state is very critical to maintain and there is a period beyond which the previous state is not just not useful, but an impediment to good user experience. It is important that apps pay attention to this and get their designs right. Some apps such as the Kindle try to maintain state at the server and sync on app launch across devices. It is not perfect, but goes after the right idea. Some apps like Twitter show you the previous position, but tell you how much new content is available. For some apps, these approaches may not make sense and they may just need to reset to a new session state.
Every app needs to consider its functionality and user experience and do the right thing. Keeping state is not always the right thing to do!