An example of shiny application with user authentication
There are two user groups: user and admin. User group can see Tab1 and change their own password. Admin group can see Tab1 and Tab2, change their own password, add/move/delete users, change email settings.
There are two uses: user1 in user group. admin1 in admin group. The password is user123 and admin123.
You will need to change the email settings in global.R if you want to use email feature in the programe.