The user shall be able to filter a view to a single feed by starred items only.

[1] A "View starred" button will be displayed to the right of the current "Refresh" and "Mark all as read" buttons while the user is viewing the feed. [see mockup: https://goo.gl/jAtqKY]

[2] When the user selects the "View starred" button, the displayed items in the feed will only be the items the user has starred. In addition, the text in the "Viewed starred" button will change to read, "Unview starred".

[3] When the "View starred" filter is active, the individual items displayed in the feed will be marked with a star icon to the immediate left of each item title.

[4] As the user selects individual starred items to read them, the filtered view to "view starred" will remain active.

[5] To disable the filtered view, the user selects the now named "Unview starred" button. (toggle on, toggle off)

Note: This is similar to but different from post 187017 entitled "Let us sort starred and liked by feed" http://theoldreader.uservoice.com/forums/187017-feature-requests/suggestions/5221542-let-us-sort-starred-and-liked-by-feed