When in process developing an Android application I stumbled on some problems of icon for the application. Fortunately, I found an amazing website for icon. The amazing website is thenounproject.com.
Why I say this website is amazing? Because they offer much of icons in free. Almost every icons are licensed under Creative Common - Attribution. So we can use them in personal or commercial application, website, or anything as long as we give a proper attribution for the icon author work. Of course we can use them without an attribution if we pay for the license which is really cheap, about $1 for each icon.
Now I can go forward developing my application... :D