Design a Website Mockup and Mobile Screens

Hello, We need partial website mockups for our web/mobile application. We do not need developers to code the actual screens on the back end. We also do not need every working screen. We just need a good designer. We will need approximately 10 desktop mockups and 10 mobile mockups of the same platform. We have rough sketches of what we'd like to see but we need someone to design it to look good. We need someone who has experience in 'flat design' and modern website and application ascetics. Please provide portfolio items that showcase only designs you have made in 'flat design' and that look modern. Please begin your application to this job with the phrase "Great Service!", so that we know you read our entire job application. Only those who do so will be considered for the job. Thanks