In-house long-term developer needed..

Looking for a sample site/app where anyone who has English knowledge can type something in English and it translates and stored in Spanish Spanish knowledge can type something in Spanish and it translates and stored in English This includes numbers, symbols like $, commonly use special characters , alphanumeric characters etc. The idea being a full-fledged site + 2 apps will be developed based on this proof of concept. This full-fledged the site will have all the bells and whistles of an e-commerce site. The main part of it is this translation engine Notes: Google has a real-time translation API that could be used for this translation piece. Output required: A sample website which has English based text box on left side , translated Spanish content on the right side If I type in English it should translate into Spanish If I type in Spanish it should translate into English This concept needs to work in a web site and android/ios apps. I am expecting just 1 web page that proves the concept. But that should be applicable in apps later when the full site , apps are developed. Complete methodology on how it can be used in a site, apps ( design , database etc) Complete costing structure (for this translation part) on what it would take to actually code a full website + 2 apps Compare other possible solutions and documentation. Complete design specs, documentation, tested source code Subsecond performance