Mobile app development

I’m looking for a mobile app developer who can help me create an app that works on both iOS and Android. I don’t have a specific design, so I am open to design suggestions, but I do have a basic idea. What I want is a mobile application that has basic features with some customizations. I need help with design and implementation and would like someone experienced and knowledgeable with mobile platforms and reliable in delivering a completed project in a timely fashion.