Android Development

Requirements are as follows: Need an Android Messaging Client with, (1) All of the existing functionality of the existing (regular) Android SMS client (including message threading, MMS support, etc?), plus (2) Callback numbers - ability of a sender to populate a field for the recipient to call him or her back (assuming it's a different number from the one the sender is using) (3) Persistent notification - client doesn't stop beeping or otherwise notifying the user that a message is there until the message is opened (or some other action is taken) (4) Encryption - an option for the user to have the incoming and outgoing messages encrypted (like AES encryption) so that someone else couldn't just pick up the phone and read the owners messages, i.e. owner would have option to set up a PIN code to get into the messaging client (5) Support for CMAS (US Commercial Mobile Alert System), which is a US governmental initiative to enable an emergency alerts to be sent out via text message - I am trying to get requirements for this? The key for us starting on this project though is not having to totally rebuild the basic messaging client. ## Deliverables (1) All of the existing functionality of the existing (regular) Android SMS client (including message threading, MMS support, etc?), plus (2) Callback numbers - ability of a sender to populate a field for the recipient to call him or her back (assuming it's a different number from the one the sender is using) (3) Persistent notification - client doesn't stop beeping or otherwise notifying the user that a message is there until the message is opened (or some other action is taken) (4) Encryption - an option for the user to have the incoming and outgoing messages encrypted (like AES encryption) so that someone else couldn't just pick up the phone and read the owners messages, i.e. owner would have option to set up a PIN code to get into the messaging client (5) Support for CMAS (US Commercial Mobile Alert System), which is a US governmental initiative to enable an emergency alerts to be sent out via text message - I am trying to get requirements for this? The key for us starting on this project though is not having to totally rebuild the basic messaging client.