Information: https://thimblefoliopress.com/projects/freebies/flat-portfolio/
This theme is a child theme for Twenty Thirteen.
This theme includes Twitter Bootstrap 2.3.2 minified css and jquery and glyphs.
Go to the Twitter Framework site to see what other components and jquery scripts you can use with this theme.

http://getbootstrap.com/

The style.css overwrites the default bootstrap styles to the flat styles- customise it however you like.
It also uses a custom nav walker: https://github.com/twittem/wp-bootstrap-navwalker

Page templates included:

Default Template- left sidebar with subpages menu for any child pages.
Full Page- full width page template.
Sub page gallery- shows subpages as a thumbnail gallery- use the child pages of a page set to this template to create a thumbnail gallery.
Gallery page – has navigation links to other pages on the same level.
Menus

top right menu
primary horizontal menu
vertical menu for sidebar

Widgets

6 widgets (2 home page footer widgets, 3 general footer widgets and a primary sidebar widget)

Custom background:

you can set a custom background in the admin.

Custom Header

you can set a custom header image in the admin.

Subpage function:

Default Template pages have a left sidebar and any child pages will show as a menu.

Thickbox for images:

It also uses thickbox (built into WordPress) for image lightboxes.
Add the to images you want to have in a lightbox.
Images uploaded and inserted onto the pages and posts will have the class added for you automatically.
You can get rid of this if you want by editing the functions.php

All functions are commented. 

Featured Thumbnails:

128px by 128px is the recommended size for thumbnails of child pages under a page using the page template for sub page gallery.

default Icons for sub pages, search pages and blog posts are free ones in a flat style.
http://www.noupe.com/freebie/exclusive-freebie-for-noupes-readers-freepiks-200-beautiful-flat-icons-77112.html