I have just set up and created by first ever SharePoint development effort: a project for a web part, to be hosted in a SharePoint Online instance (my Office 365 trial).
I have figured out how to use the List API to pull the content I am supposed to present, being a rotating list of banner images, but I have one remaining concern. I would like to keep track of where in the list I am, and when last I changed images. Another question of mine answers this quite nicely if I go with local storage, but is there any SharePoint REST or JSOM API I can use to persist this state in the SharePoint service?