A community mobile optimized application

building a mobile friendly app using Wordpress I am basically looking for a very basic generic platform that: 1) registers users, but the users are by default anonymous. They can decide to change to non-anonymous, their choice. Once users has registered, how can we ensure they are safely kept connected and don't have to re-login, each time they visit the app 2) personal information collected, must include race, religion and ethnicity. This is collected to give credit to the race, religion and ethnicity. Some profits of this company will be allocated every year to help the communities most supporting our efforts, by registering and actively participating. This data collect will not be viewable by anybody. It will be used to tabulate which community is supporting us most via nice graphics. This will let us and the people know. Which communities are participating or not. 3) users can submit post that contains heading, full text, images, videos, MEME's etc, easily. This could be a brand new post created by users or sharing post from FB, other major social media apps and major news media 4) users can share post from our app to FB, Twitter and other major social media apps. It will give users of other social media apps to see a summary to know what is the post all about, but to view full post and text and participate in discussions or surveys, users will be directed to my app. This is how we will acquire new users to register with us. Of course, we will have admin of the app that can mass load complete post with headings, full text, images and videos 5) users on other social media apps can take the surveys, but for results, they would be pulled into my app, thus giving them a chance to view details related to survey, MEME's or post 6) community can give each post a rating of 0 to 5 stars. Community can comment, reply and be able to edit and delete their own comments/replies 7) post can be sorted by number of stars, post types or world regions and countries 8) all post by users will be reviewed and approved by app admin to ensure appropriateness of post for our community and spam 9) all post must be checked for no use of bad language 10) post can be articles, MEME's, video, images, etc. Post can also be a survey with agree disagree options or multiple choice selection 11) app can send email to users via email. App can send alert to user mobile devices to inform that weekly/monthly news letter is available or a news breaking summary alert 12) user interface must be very simple, intuitive and beautiful that users do not want to leave it Please let me know if there is some basic functionality that I would need, but did not mention per your knowledge and experience. Please let me know how long will it take to build this platform for me and what would the cost be? Also, performance around the globe must be good, because there will be a lot of users from all over the world. Must be able to handle millions of users. Please let me know any limitations of this platform that might cause problems if the the number of users goes into the 10 or 100 of million users. Thanks, Harjit