Q:

Offline GEDCOM viewer for Chromebook

I am looking for a simple genealogy package that will run on a Chromebook.
The package only has to be able to display a GEDCOM file in a tree format on 
the Chromebook when disconnected from the internet.  I don't require full 
family tree editing facilities as that can be done when online through web 
services or on a separate Windows PC.
Cross-platform java-based viewers such as 

StarkEffect  don't work on my Chromebook.  Although, something similar would be ideal.

A:

Dick Eastman in his Online Genealogy Newsletter wrote a post: Why Use a Chromebook?
In it he said:

For a genealogist, a major disadvantage of a Chromebook is the lack of
  a good genealogy program. A few, small genealogy utilities are
  available but nothing that approaches the capabilities of RootsMagic,
  Legacy Family Tree, The Master Genealogist, Reunion, Heredis,
  MacFamilyTree, Ancestral Quest, GRAMPS, Family Tree Maker, or the
  other popular genealogy programs available today for Windows and
  Macintosh. However, when connected to the Internet, a Chromebook works
  well with most all the online genealogy applications, such as The Next
  Generation (TNG) and PhpGedView. It also works well with almost all
  the genealogy web sites, including FamilySearch, MyHeritage, WeRelate,
  Ancestry, Geni, WikiTree, and many, many more.

There are several online sites that will do what you want. But you want to do it when disconnected from the internet, so it sounds like you'll need a native Chrome application for that. 
Unfortunately none of the Chrome genealogy applications (6 at the time I'm writing this) listed in the chrome web store will do what you want, so you may be out of luck.

