Makeappicon is a free and web-based tool for generating app icons quickly.
It works by simply uploading a big-sized image and the app auto-resizes it to the required dimensions.
The sizes are the ones that are required by iOS + Android apps.
Makeappicon accepts .JPG, .PNG and .PSD files (works best with a 1024*1024px image).
Batch is a slick set of free icons that can easily beautify our web or app user interfaces.
There are 300 items in the set where each one of them comes as a Photoshop shape so that they can scale infinitely.
The set is completely free to use in both free and commercial projects.
Endless Icons is a website which regularly features a new icon every few days.
All the icons are black and white colored and there are sketchy/hand-drawn ones as well.
It features icons of charts, foods, sports and various other elements (kinda random).
They are all free-to-use in personal + commercial projects and come in PNG format.
Here is a fresh and very useful icon font which can easily fit to any websites and apps: Ligature Symbols.
This free icon font consists of 200+ letters with items like actions, smileys and more. Also, a huge number of social icons are included.
The download pack has all the versions (SVG, EOT, TTF, WOFF) needed for cross-browser support and the styles needed to use it.
There are many social networks, apps, programs and frameworks which are being used widely.
Pictonic Free is a huge icon font which has most of the popular items from the categories above and also includes browsers, operating systems and databases.
There are 220+ icons (letters) and it is a pretty useful set for icon font fans.
Codrops is sharing a beautiful freebie that web designers/developers will like so much.
It is a pack of 120 slick icons named "Application Icon Set" where the set comes in 3 sizes: 16*16px, 32*32px and 64*64px.
There are 3 formats provided: transparent PNG, PSD and CSH (custom shape) which is great as we can scale them as needed.
As the name suggests, the icon set is focused on apps and includes items that are frequently used in them.
Modern UI Icons (also named Windows Phone Icon Pack) is a set of 750+ very beautifully designed icons.
The icons are created with Windows Phone and Windows 8 developers in mind, however, they can fit very well to any web/mobile/desktop project.
This set was featured at WRD before when there was ~140 icons but it has grew so much, moved into a new domain and deserves a 2nd shot.
They are designed with Expression Design and comes with 48*48px PNG (light and dark), .design and .XAML versions.
It includes many items from actions to filetypes, weather, charts and much more.
Just like "there is never too much icons", there is also never too much icon fonts and here is a new one.
Sosa is a free icon font with 120+ items under categories like web, social, e-commerce, forms, weather and more.
It comes in multiple formats: .ttf .eot .svg + .woff and can be consumed with
@font-face CSS property.
Typicons is a beautiful set of free icons that is built with websites/apps in mind.
The set comes as a web-font and vector (.EPS) so that you can use it in multiple ways.
There are 90+ items in the pack and they can be used for both free + commercial projects.
P.S. You should also check another WRD post for more icon fonts: Free Icon Fonts For Today's Web Designer.
IconShock, the well-known icon design company, is sharing a very nice set of free user icons.
The set includes 100 items in different combinations, single users (male/female) and groups of users with different designs.
They are offered in multiple versions: iPhone, Android, Windows and colored. And, the items are packed in PNG + PSD files.
Also, a vector version (.AI) is included for maximum customization.
And, if you are in search for for more freebies, check this site for free vector.