Create a Save Session widget like the custom widget developed by the community for Webapp builder:
https://github.com/softwhere/SaveSession-Widget
This would allow users to save all session information including: the status of layers, graphics, map location etc as a json file so that it can be saved in a filestore or shared with other users, so that once loaded at next run time a user can pick up a project from where they left off.
Full details of existing web appbuilder functionality is available at the github resource above.
