These extensions are especially useful for webmasters. That’s why, I made another post for these three useful extensions.
MeasureIt: After installation, a button appears on the statusbar of the Firefox. Just click it and drag on the webpage to measure the width and height of a particular area. It is helpful for me while measuring the banners and images to be inserted.
Description: “Draw a ruler across any webpage to check the width, height, or alignment of page elements in pixels.”
ColorZilla: Another useful extension. It also makes a button on the statusbar of the Firefox. Click on it and click on the image or text to read the color of it. It also has eyedropper built in it. I use it in designing my blogs and sites.
Description: “Advanced Eyedropper, ColorPicker, Page Zoomer and other colorful goodies.
With ColorZilla you can get a color reading from any point in your browser, quickly adjust this color and paste it into another program. You can Zoom the page you are viewing and measure distances between any two points on the page. The built-in palette browser allows choosing colors from pre-defined color sets and saving the most used colors in custom palettes. DOM spying features allow getting various information about DOM elements quickly and easily. And there’s more…”
Description: “Adsense Notifier simply shows your adsense stats on the status bar and updates the stats automatically. This is wonderful for anyone with OCD ( or GAD as some have called it ) who needs to check their stats every three seconds to see if they have gotten any more clicks :-p”