android app development

MODULE [login to view URL] management: -users should be able to block contacts(phone number),so that the block contact cannot send messages to the user who blocked him -users should be able to view contacts(phone number),users should be able to view other users who are registered users and their phone numbers must be in the system and a user must have the other users contacts in the phone for him/her to view the contact in the app -users should be able to sync contacts(phone number),it syncs the data from your phone onto the service's servers. That way if you switch phones, if your new phone would have Syncing capability, you could retrieve your contacts and documents back to the phone. -users should be able to search contacts(phone number) of other users if the user has the contacts of the other users in the app users should be able to upload/add contacts(phone number),a user should be able to enter a contact and if the entered contact is a registered user it will appear in the contacts section of the app,if the contact is not a registered user the contact will not appear in contacts section of the app [login to view URL] synchronization-what appears in a user's phone who is the sender(s) is also seen on the recipient(s)phone 3.Encryption-encrypt/ encoding messages in the server so that the messages cannot be read by any user or other people [login to view URL] user interface-there is a chat app that already exists so you are going to change the whole interface/app appearance [login to view URL] admin panel to manage user data-a website is needed to view and manage user data I have the designs of the app There is a documentation you will be provided with. i do plan to invest in database analysis and design It's modification of an existing app