website designing and app creation

I am looking to have a website designed, as well as an app created for both iOS and Android platforms. I have some specific design preferences in mind, and want the app to have features such as user profiles and authentication. I am open to suggestions and welcome any inspiring examples that will help me create exactly the look and feel I am going for. If the app requires custom functionality, please let me know what is needed and your estimated cost for this. Thank you for considering my project.