Windows 7 Icons

Mar 30, 2014 Application Icons for Windows and Mac OS

Application icon is typically displayed in the top-left corner of application's top-level windows. For windows, the icons format should be in .ico extension and the application icon size should include: 16x16, 32x32, 48x48 and 256x256. Also windows 8 support 30х30, 50x50 and 150x150 application icon. For toolbar icons, use the .png format. You can also change the default icons by using ICONION tool.
Mar 20, 2014 Symbol font icon vs image icon

It helps to move the tiny icons into a single file of fonts. Many high-traffic websites have replaced their site’s image icons into single symbol fonts. These fonts are used as icons, glyphs, and decorations. This problem cannot bring effect for most of the users, as many of them have utility icons for better social networking scale and feeds.
Mar 12, 2014 Twitter Bootstrap Icons

Bootstrap is among the web's most popular free open source tools, used for developing websites and other online elements, such as creating icons, buttons, forms and other elements online. Twitter's Bootstrap interface enables users to insert various Bootstrap icons, ranging from retweet icons, to arrows, hearts and stars and other symbols, also called glyphicons. In all, there are approximately Twitter bootstrap icons.

Iconion: awesome icon creator