Write an Iphone/Android application and server software

We need a software developer who can develop a cross platform social networking app (Android and iPhone) along with needed server software. We want the same company to handle the development of both the client and the server, and we have the following requirements for each: Client We will need clients for both Android and iPhone, so we would prefer the use of some type of cross-platform development if possible. The client application will need to be able to post text, images, and/or short videos (15 secs or less) to the app for upload to the server. The client will need to display the posted information from a feed downloaded from the server. The client will also need chat and to initiate chats with other users of the system (via the server). User management and login will be needed. The client will need the ability to input settings such as demographic information (e.g., birthdate, gender, etc.) as well as interface with phone location services to determine the location of the client app and provide notices to the user regarding incoming messages (even when the app is not running). Server We need a scalable server side system that can manage the following services of the app. We are willing to look at suggested back-end systems for scaling, including cloud computer systems or other suggestions. Feed Management The server software will need accept new posts from users and validate the posts The server software will need to determine who should receive each post and make sure to update their feed list The server software will have to appropriately cache information so as to scale check against feeds Login management The server will need to keep track of each user and password, and it will need to be able to keep track of information about each user The server will have to validate logins and manage forgotten passwords Chats The server will need to send chat messages to the correct users in both one-on one (direct) chats The server will need to manage the ability to administer chats with kicks/bans and to manage the persistence of chats The chats will have the ability to send images/video just like full posting, so it will need to manage that as well