Green Chat with all people you love
Feature
1. Signin, signout, register.
Register: allow user register a new account with username and password
Signin: user must signin with username and password to use app.
Forgot password: connect to Firebase service to reset password.
Edit profile: change avatar image, edit username.
2. Chat, group chat
Chat with friend: add friend, unfriend, send text message.
Chat in group: create group, add member, kickoff member, delete group and rename.