Here is a iOS Tab Bar Icon Set, which will help each iPhone or iPad application developer get his graphic user interface in order.
A wide range of buttons, including symbols for User, Business, Camera, Zoom, E-mail, Cut, Copy, Save, Profile, Search, Help, Lock and Unlock, along with navigation arrows and lots of other general purpose graphics is included into this collection. All the images have a transparent background and are available in two colors: black and white.
Technically, there are 565 unique app icons created in matching style in a PNG format. The sizes for navigation bars of the following devices are available: 20x20 and 40x40 pixels (high resolution) for iPhone and iPod touch, 20x20 pixels for iPad. The tab bar sizes include a 30x30 pixels icons for iPad and 30x30 and 60x60 pixels icons for iPhone and iPod touch.
All the icons from this set are available for immediate online preview. A trial download is also provided for your convenience.
After you've decided on the appearance of your icon, follow these guidelines as you create it:
Use pure white with appropriate alpha transparency.
Do not include a drop shadow.
Use anti-aliasing.
If you decide to add a bevel, be sure that it is 90 degrees (to help you do this, imagine a light source positioned at the top of the icon).
For toolbar and navigation bar icons, create an icon in the following sizes:
For iPhone and iPod touch:
About 20 x 20 pixels
About 40 x 40 pixels (high resolution)
For iPad:
About 20 x 20 pixels
For tab bar icons, create an icon in the following sizes:
For iPhone and iPod touch:
About 30 x 30 pixels
About 60 x 60 pixels (high resolution)
For iPad:
About 30 x 30 pixels