Oh, and it looks like the feed API may not be used to save anything; Google's API ToS [1] document has the following text:

    Unless expressly permitted by the content owner
    or by applicable law, you agree that you will
    not, and will not permit your end users to, do
    the following with content returned from the APIs:

    * Scrape, build databases or otherwise create 
    permanent copies of such content, or keep cached 
    copies longer than permitted by the cache header;
    * Copy, translate, modify, create a derivative 
    work of, sell, lease, lend, convey, distribute, 
    publicly display or sublicense to any third party;
    * Misrepresent the source or ownership; or
    * Remove, obscure, or alter any copyright, 
    trademark or other proprietary rights notices,
    falsify or delete any author attributions, legal
    notices or other labels of the origin or source 
    of material.

The first two bullet points are the ones that apply. You can't use the feed API to fetch a bunch of feeds and make them available through an app, for example.

[1] https://developers.google.com/terms/

According to the ToS at https://developers.google.com/feed/terms:

    Google will announce if we intend to discontinue
    or make backwards incompatible changes to this 
    API or Service. We will use commercially
    reasonable efforts to continue to operate the 
    Google Feed API without these changes until 
    April 20, 2015, unless (as Google determines in 
    its reasonable good faith judgment):

    * required by law or third party relationship 
    (including if there is a change in applicable 
    law or relationship), or
    * doing so could create a security risk or 
    substantial economic or material technical 
    burden.

    This Deprecation Policy doesn't apply to 
    versions, features, and functionality labeled 
    as "experimental."

Of course, who knows what "commercially reasonable efforts" really mean.