Dear Mr. Manager,
I have just seen your Job posting and upon reading thoroughly, I felt strongly that I would be the most qualified contractor for this project.
I'm an experienced front end Developer having proven quality experience in developing high-end responsive websites.
I have also top skills of HTML, HTML5, CSS, CSS3, bootstrap, jQuery, PHP, Ajax, etc.
All of the sites I build are 100% responsive, with clean HTML5 and CSS, and only the most reliable javascript plugins, which results in beautifully-simple websites, with app-like mobile experiences.
I am looking forward to hearing from you soon.
I believe my skills would be ideal for your project.