this is a android instant messenger based on socket communication
basic functionality:
- a user can register an account with a username, his/her age and gender
- login with username and password
- find out friends by username or particulars(age and gender)
- chat with a friend with text and emoji
- chatting history available for checking
- messages sent to offline friends will be saved at server and pushed to that friend when he/she signs in
- ringtone and vibration notification when a message arrived if messanger is not foreground