Convert websites to mobile

Hello Im looking to work with someone that can convert websites to mobile devices. I make websites for clients and want to offer them the option to have their site mobile device enabled. Any experts in this area let me know as I can offer this to many of my existing and future clients. If you are interested, let me know: 1. The url of a website which I can then test in my phone 2. A flat rate cost to convert a website bearing in mind I will always have this requirement for you. Thanks Rakesh