How to Change Fonts on Facebook,Twitter or any other sites

Are you bored of the old fonts of Gmail, Twitter, Facebook, Blogger or any other site and want to change the fonts of the sites. Now, a developers of google scripts created a apps to change the sites fonts. This Fonts changer apps has more than 500 styles with a great collection.You can also use your custom fonts, you just have to upload your fonts in .ttf, woff, .otf format and use that fonts