StateSaver is an excellent addition to the UITK. However, making adding it a manual process removes almost all of the point of it, because we're requiring developers to go to extra effort to make their apps do something that all apps ought to do automatically. We want Ubuntu apps to provide a great user experience; remembering state is part of that, and should be done automatically rather than requiring it it be explicitly manually enabled. This helps to create a culture where Ubuntu apps Do The Right Thing and so apps which do not DTRT are the odd ones, rather than remembering state being an extra feature which only the best apps do. It improves the platform as a whole, and helps users expect that an Ubuntu app will be good rather than being pleasantly surprised when that happens. I suggest that StateSaver should be enabled on relevant properties for UITK widgets (scroll position for a ListView, content for a text entry, selected Tab for Tabs, etc) by default, and that that be a requirement for new widgets aded to the UITK.
This has been on roadmaps for some time, unfortunately higher priority task forces pushed down its importance.
First, we have to make sure StateSaver has teh option to permanently save a state, yet wipes out all the states on normal application close, and keeps them only on SIGINT or SIGTERM. However even this data is wiped with a reboot.