Green Chat

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.