Any developer can use set of professionally desinged royalty free icons.

“Silk” is a smooth, free icon set, containing over 700  16-by-16 pixel icons in strokably-soft PNG format. Containing a large variety of icons, you're sure to find something that tickles your fancy. And all for a low low price of $0.00. You can't say fairer than that.

http://www.famfamfam.com/lab/icons/silk/