Is there an Android App for automated attendance system?

[AC Question]

Android App for Automated Attendance System

I want to create an Android app for Automated Attendance System in which the app can dedect Automatically the number of studnets present in the class room with the help of bluetooth. That is at the time of attendance the user can use the Android app directly to record the one unique id of the Android app installed on the mobile phone of the students and later the record gets updated iin the database. so is it possible to get the unique id of all the bluetooth connected in that class room ..if yes the how can it be possible

 

[saltracker]

I would like to determine if one smartphone ( latest versions that are able to run Marshmallow ) running android Marshmallow 6 is able to handle multiple fingerprint logins ie for a factory ie can it register more than one user and if so is their a limit to this - some of the rugged android phones (eg autoteco ) are able to register 1000 of users on one device